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Singha R, Dalgaard KJ, Marchenko D, Krivenkov M, Rienks EDL, Jovanovic M, Teicher SML, Hu J, Salters TH, Lin J, Varykhalov A, Ong NP, Schoop LM. Colossal magnetoresistance in the multiple wave vector charge density wave regime of an antiferromagnetic Dirac semimetal. SCIENCE ADVANCES 2023; 9:eadh0145. [PMID: 37831777 PMCID: PMC10575584 DOI: 10.1126/sciadv.adh0145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 09/11/2023] [Indexed: 10/15/2023]
Abstract
Colossal negative magnetoresistance is a well-known phenomenon, notably observed in hole-doped ferromagnetic manganites. It remains a major research topic due to its potential in technological applications. In contrast, topological semimetals show large but positive magnetoresistance, originated from the high-mobility charge carriers. Here, we show that in the highly electron-doped region, the Dirac semimetal CeSbTe demonstrates similar properties as the manganites. CeSb0.11Te1.90 hosts multiple charge density wave modulation vectors and has a complex magnetic phase diagram. We confirm that this compound is an antiferromagnetic Dirac semimetal. Despite having a metallic Fermi surface, the electronic transport properties are semiconductor-like and deviate from known theoretical models. An external magnetic field induces a semiconductor metal-like transition, which results in a colossal negative magnetoresistance. Moreover, signatures of the coupling between the charge density wave and a spin modulation are observed in resistivity. This spin modulation also produces a giant anomalous Hall response.
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Affiliation(s)
- Ratnadwip Singha
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | | | - Dmitry Marchenko
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - Maxim Krivenkov
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - Emile D. L. Rienks
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - Milena Jovanovic
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Samuel M. L. Teicher
- Materials Department and Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, CA. 93106, USA
| | - Jiayi Hu
- Department of Physics, Princeton University, Princeton, NJ 08544, USA
| | - Tyger H. Salters
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Jingjing Lin
- Department of Physics, Princeton University, Princeton, NJ 08544, USA
| | - Andrei Varykhalov
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - N. Phuan Ong
- Department of Physics, Princeton University, Princeton, NJ 08544, USA
| | - Leslie M. Schoop
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
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Hall Effect Anisotropy in the Paramagnetic Phase of Ho 0.8Lu 0.2B 12 Induced by Dynamic Charge Stripes. Molecules 2023; 28:molecules28020676. [PMID: 36677734 PMCID: PMC9863903 DOI: 10.3390/molecules28020676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/22/2022] [Accepted: 12/31/2022] [Indexed: 01/11/2023] Open
Abstract
A detailed study of charge transport in the paramagnetic phase of the cage-cluster dodecaboride Ho0.8Lu0.2B12 with an instability both of the fcc lattice (cooperative Jahn−Teller effect) and the electronic structure (dynamic charge stripes) was carried out at temperatures 1.9−300 K in magnetic fields up to 80 kOe. Four mono-domain single crystals of Ho0.8Lu0.2B12 samples with different crystal axis orientation were investigated in order to establish the singularities of Hall effect, which develop due to (i) the electronic phase separation (stripes) and (ii) formation of the disordered cage-glass state below T*~60 K. It was demonstrated that a considerable intrinsic anisotropic positive component ρanxy appears at low temperatures in addition to the ordinary negative Hall resistivity contribution in magnetic fields above 40 kOe applied along the [001] and [110] axes. A relation between anomalous components of the resistivity tensor ρanxy~ρanxx1.7 was found for H||[001] below T*~60 K, and a power law ρanxy~ρanxx0.83 for the orientation H||[110] at temperatures T < TS~15 K. It is argued that below characteristic temperature TS~15 K the anomalous odd ρanxy(T) and even ρanxx(T) parts of the resistivity tensor may be interpreted in terms of formation of long chains in the filamentary structure of fluctuating charges (stripes). We assume that these ρanxy(H||[001]) and ρanxy(H||[110]) components represent the intrinsic (Berry phase contribution) and extrinsic (skew scattering) mechanism, respectively. Apart from them, an additional ferromagnetic contribution to both isotropic and anisotropic components in the Hall signal was registered and attributed to the effect of magnetic polarization of 5d states (ferromagnetic nano-domains) in the conduction band of Ho0.8Lu0.2B12.
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Yang H, Konečná A, Xu X, Cheong SW, Batson PE, García de Abajo FJ, Garfunkel E. Simultaneous Imaging of Dopants and Free Charge Carriers by Monochromated EELS. ACS NANO 2022; 16:18795-18805. [PMID: 36317944 DOI: 10.1021/acsnano.2c07540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Doping inhomogeneities in solids are not uncommon, but their microscopic observation and understanding are limited due to the lack of bulk-sensitive experimental techniques with high enough spatial and spectral resolution. Here, we demonstrate nanoscale imaging of both dopants and free charge carriers in La-doped BaSnO3 (BLSO) using high-resolution electron energy-loss spectroscopy (EELS). By analyzing high- and low-energy excitations in EELS, we reveal chemical and electronic inhomogeneities within a single BLSO nanocrystal. The inhomogeneous doping leads to distinctive localized infrared surface plasmons, including a previously unobserved plasmon mode that is highly confined between high- and low-doping regions. We further quantify the carrier density, effective mass, and dopant activation percentage by EELS and transport measurements on the bulk single crystals of BLSO. These results not only represent a practical approach for studying heterogeneities in solids and understanding structure-property relationships at the nanoscale, but also demonstrate the possibility of infrared plasmon tuning by leveraging nanoscale doping texture.
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Affiliation(s)
- Hongbin Yang
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey08854, United States
| | - Andrea Konečná
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860Castelldefels, Barcelona, Spain
- Central European Institute of Technology, Brno University of Technology, 61200Brno, Czech Republic
| | - Xianghan Xu
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey08854, United States
| | - Sang-Wook Cheong
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey08854, United States
| | - Philip E Batson
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey08854, United States
| | - F Javier García de Abajo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860Castelldefels, Barcelona, Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys 23, 08010Barcelona, Spain
| | - Eric Garfunkel
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey08854, United States
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey08854, United States
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Yamada S, Sagayama H, Yamazaki M, Aoki H, Sugimoto K, Arima T. Physical properties and phase diagram of single crystal REBaMn2O6 (RE = Sm, Eu, Gd, Tb, Dy, and Y). J SOLID STATE CHEM 2022. [DOI: 10.1016/j.jssc.2022.123504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Mero RD, Ogawa K, Yamada S, Liu HL. Optical Studies on the Phase Transitions in YBaMn 2O 6 Single Crystals. ACS OMEGA 2021; 6:22137-22150. [PMID: 34497905 PMCID: PMC8412917 DOI: 10.1021/acsomega.1c02763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 08/13/2021] [Indexed: 06/13/2023]
Abstract
The double perovskite YBaMn2O6 exhibited complex structural, magnetic, and charge/orbital ordering phase transitions. In this paper, we investigated the correlation between the temperature-dependent optical response and complex phase transitions of YBaMn2O6 single crystals through spectroscopic ellipsometry and Raman scattering spectroscopy. The room temperature optical absorption spectrum of YBaMn2O6 revealed three bands of approximately 1.50, 4.05, and 5.49 eV. The lowest optical absorption band was assigned to on-site d-d transitions in Mn ions, whereas the other two optical features were assigned to charge-transfer transitions between the 2p states of O and 3d states of Mn. The room temperature Raman scattering spectrum revealed 25 phonon modes. Notably, the MnO6 octahedral tilting and bending modes between 360 and 440 cm-1 increased in intensity at temperatures <200 K. Furthermore, several new phonon peaks appeared at temperatures <200 K, which were associated with charge ordering. Additionally, the magnetic order-induced changes were observed in the breathing modes, with reduced intensity of the 620 cm-1 and a substantial enhancement of the 644 cm-1 phonon peaks. The Jahn-Teller mode at approximately 496 cm-1 exhibited strong hardening at temperatures <200 K, which indicated a linear correlation with the square of the magnetic susceptibility and thus revealed the occurrence of spin-phonon coupling. Anomalies in the phonon frequency, line width, and intensity observed near the phase transition temperatures highlighted the importance of lattice-charge-spin interactions in YBaMn2O6.
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Affiliation(s)
- Rea Divina Mero
- Department
of Physics, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Kirari Ogawa
- Department
of Material System Science, Yokohama City
University, Yokohama 236-0027, Japan
| | - Shigeki Yamada
- Department
of Material System Science, Yokohama City
University, Yokohama 236-0027, Japan
| | - Hsiang-Lin Liu
- Department
of Physics, National Taiwan Normal University, Taipei 11677, Taiwan
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Direct experimental evidence of physical origin of electronic phase separation in manganites. Proc Natl Acad Sci U S A 2020; 117:7090-7094. [PMID: 32179681 DOI: 10.1073/pnas.1920502117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Electronic phase separation in complex oxides is the inhomogeneous spatial distribution of electronic phases, involving length scales much larger than those of structural defects or nonuniform distribution of chemical dopants. While experimental efforts focused on phase separation and established its correlation with nonlinear responses under external stimuli, it remains controversial whether phase separation requires quenched disorder for its realization. Early theory predicted that if perfectly "clean" samples could be grown, both phase separation and nonlinearities would be replaced by a bicritical-like phase diagram. Here, using a layer-by-layer superlattice growth technique we fabricate a fully chemically ordered "tricolor" manganite superlattice, and compare its properties with those of isovalent alloyed manganite films. Remarkably, the fully ordered manganite does not exhibit phase separation, while its presence is pronounced in the alloy. This suggests that chemical-doping-induced disorder is crucial to stabilize the potentially useful nonlinear responses of manganites, as theory predicted.
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Mero RD, Ogawa K, Yamada S, Liu HL. Optical Study of the Electronic Structure and Lattice Dynamics of NdBaMn 2O 6 Single Crystals. Sci Rep 2019; 9:18164. [PMID: 31796772 PMCID: PMC6890712 DOI: 10.1038/s41598-019-54524-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 09/20/2019] [Indexed: 11/23/2022] Open
Abstract
We investigated the electronic structure and lattice dynamics of double perovskite NdBaMn2O6 single crystals through spectroscopic ellipsometry and Raman scattering spectroscopy. The optical absorption band centered at approximately 0.88 eV was assigned to on-site d–d transitions in Mn, whereas the optical feature at approximately 4.10 eV was assigned to charge-transfer transitions between the 2p state of O and 3d state of Mn. Analysis of the temperature dependence of the d-d transition indicated anomalies at 290 and 235 K. The activated phonon mode, which appeared at approximately 440 cm−1 alongside with the enhancement of the 270 cm−1 phonon mode, coupled strongly to the metal–insulator transition at 290 K, which was associated with a charge/orbital ordering. Moreover, the MnO6 octahedral breathing mode at 610 cm−1 exhibited softening at a temperature lower than 235 K (temperature of the antiferromagnetic phase transition), which revealed the strong coupling between the lattice and magnetic degrees of freedom. The spin–phonon coupling constant obtained was λ = 2.5 cm−1. These findings highlight the importance of charge–orbital–spin interactions in establishing NdBaMn2O6 phases with novel properties.
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Affiliation(s)
- Rea Divina Mero
- Department of Physics, National Taiwan Normal University, Taipei, 11677, Taiwan
| | - Kirari Ogawa
- Department of Material System Science, Yokohama City University, Yokohama, 236-0027, Japan
| | - Shigeki Yamada
- Department of Material System Science, Yokohama City University, Yokohama, 236-0027, Japan
| | - Hsiang-Lin Liu
- Department of Physics, National Taiwan Normal University, Taipei, 11677, Taiwan.
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A-site ordered state in manganites with perovskite-like structure based on optimally doped compounds Ln0.70Ba0.30MnO3 (Ln = Pr, Nd). J RARE EARTH 2019. [DOI: 10.1016/j.jre.2018.12.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Yamada S, Abe N, Sagayama H, Ogawa K, Yamagami T, Arima T. Room-Temperature Low-Field Colossal Magnetoresistance in Double-Perovskite Manganite. PHYSICAL REVIEW LETTERS 2019; 123:126602. [PMID: 31633958 DOI: 10.1103/physrevlett.123.126602] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Indexed: 06/10/2023]
Abstract
We have discovered room-temperature low-field colossal magnetoresistance (CMR) in an A-site ordered NdBaMn_{2}O_{6} crystal. The resistance changes more than 2 orders of magnitude at a magnetic field lower than 2 T near 300 K. When the temperature and magnetic field sweep from an insulating (metallic) phase to a metallic (insulating) phase, the insulating (metallic) conduction changes to the metallic (insulating) conduction within 1 K and 0.5 T, respectively. The CMR is ascribed to the melting of the charge and orbital ordering. The entropy change which is estimated from the B-T phase diagram is smaller than what is expected for the charge and orbital ordering. The suppression of the entropy change is attributable to the loss of the short-range ferromagnetic fluctuation of Mn spin moments, which is an important key of the high temperature and low magnetic field CMR effect.
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Affiliation(s)
- S Yamada
- Department of Materials System Science, Yokohama City University, Yokohama 236-0027, Japan
| | - N Abe
- Department of Advanced Materials Science, The University of Tokyo, Kashiwa 277-8561, Japan
| | - H Sagayama
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan
- Department of Materials Structure Science, The Graduate University for Advanced Studies, Tsukuba, Ibaraki 305-0801, Japan
| | - K Ogawa
- Department of Materials System Science, Yokohama City University, Yokohama 236-0027, Japan
| | - T Yamagami
- Department of Materials System Science, Yokohama City University, Yokohama 236-0027, Japan
| | - T Arima
- Department of Advanced Materials Science, The University of Tokyo, Kashiwa 277-8561, Japan
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Vlcek L, Ziatdinov M, Maksov A, Tselev A, Baddorf AP, Kalinin SV, Vasudevan RK. Learning from Imperfections: Predicting Structure and Thermodynamics from Atomic Imaging of Fluctuations. ACS NANO 2019; 13:718-727. [PMID: 30609895 DOI: 10.1021/acsnano.8b07980] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In materials characterization, traditionally a single experimental sample is used to derive information about a single point in the composition space, while the imperfections, impurities, and stochastic details of material structure are deemed irrelevant or complicating factors in the analysis. Here we demonstrate that atomic-scale studies of a single nominal composition can provide information about microstructures and thermodynamic response over a finite area of chemical space. Using the principles of statistical inference, we develop a framework for incorporating structural fluctuations into statistical mechanical models and use it to solve the inverse problem of deriving effective interatomic interactions responsible for elemental segregation in a La5/8Ca3/8MnO3 thin film. The results are further analyzed by a variational autoencoder to detect anomalous behavior in the composition phase diagram. This study provides a framework for creating generative models from a combination of multiple experimental data and provides direct insight into the driving forces for cation segregation in manganites.
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Affiliation(s)
- Lukas Vlcek
- Joint Institute for Computational Sciences , University of Tennessee , Knoxville , Tennessee 37996 , United States
| | | | - Artem Maksov
- UT Bredesen Center for Interdisciplinary Research , University of Tennessee , Knoxville , Tennessee 37996 , United States
| | - Alexander Tselev
- Department of Physics , CICECO - Aveiro Institute of Materials , 3810-193 Aveiro , Portugal
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Taguchi Y, Sakai H, Choudhury D. Magnetocaloric Materials with Multiple Instabilities. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1606144. [PMID: 28387437 DOI: 10.1002/adma.201606144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 01/30/2017] [Indexed: 06/07/2023]
Abstract
The magnetocaloric effect is a well-known phenomenon where the temperature of a magnetic material varies upon application or removal of a magnetic field. This effect is anticipated to be applied to magnetic refrigeration technology, which is environmentally benign. For practical applications, it is essential to explore and expand the materials horizon of novel magnets that exhibit giant magnetocaloric effects to achieve sufficient cooling efficiency. In this article, several attempts to enhance the magnetocaloric effect are reviewed from the viewpoint of the competition or cooperation between the ferromagnetic interaction and other magnetic, electronic, and structural instabilities in strongly correlated materials. The results indicate that both the competition and cooperation between them promote the first-order nature of the magnetic transition, leading to giant magnetocaloric effects. Therefore, exploiting multiple instabilities is a promising strategy for exploring new magnetocaloric materials.
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Affiliation(s)
- Yasujiro Taguchi
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan
| | - Hideaki Sakai
- Department of Physics, Osaka University, Toyonaka, 560-0043, Japan
- Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, Kawaguchi, 332-0012, Japan
| | - Debraj Choudhury
- Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India
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Pradheesh R, Nair HS, Haripriya GR, Senyshyn A, Chatterji T, Sankaranarayanan V, Sethupathi K. Magnetic glass state and magnetoresistance in SrLaFeCoO 6 double perovskite. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:095801. [PMID: 28106011 DOI: 10.1088/1361-648x/aa5470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Unusual features in magnetization resembling the kinetic arrest of a magnetic glass state are observed in the La-doped double perovskite, SrLaFeCoO6. Neutron powder diffraction experiments confirm the presence of antisite disorder as well as a lack of long-range magnetic order down to 4 K in this double perovskite which displays spin glass-like features in dc and ac susceptibilities. Magnetic relaxation observed through cooling and heating under unequal fields (CHUF) point towards unusual domain dynamics which is supported by a broad memory effect. Among the two anomalies that are observed at [Formula: see text] 75 K and at [Formula: see text] 250 K in the magnetic measurements, the former is associated with a spin-freezing temperature below which the magnetic glass state is experimentally verified. The magnetometric experiments detailed in the paper bring out the non-equilibrium metastable magnetic states in this disordered magnetic system. The magnetic glass state described above manifests in the electrical resistivity [Formula: see text] through the formation of a 'hard gap' because of the spin-exchange energy following the formation of magnetic glass. It is observed that the combination of disorder and magnetic glass state leads to a large, negative magnetoresistance (MR) of ≈47[Formula: see text] at 5 K in 8 T.
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Affiliation(s)
- R Pradheesh
- Department of Physics, Low Temperature Physics Lab, Indian Institute of Technology Madras, Chennai 600036, India
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Liu M, Sternbach AJ, Basov DN. Nanoscale electrodynamics of strongly correlated quantum materials. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2017; 80:014501. [PMID: 27811387 DOI: 10.1088/0034-4885/80/1/014501] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Electronic, magnetic, and structural phase inhomogeneities are ubiquitous in strongly correlated quantum materials. The characteristic length scales of the phase inhomogeneities can range from atomic to mesoscopic, depending on their microscopic origins as well as various sample dependent factors. Therefore, progress with the understanding of correlated phenomena critically depends on the experimental techniques suitable to provide appropriate spatial resolution. This requirement is difficult to meet for some of the most informative methods in condensed matter physics, including infrared and optical spectroscopy. Yet, recent developments in near-field optics and imaging enabled a detailed characterization of the electromagnetic response with a spatial resolution down to 10 nm. Thus it is now feasible to exploit at the nanoscale well-established capabilities of optical methods for characterization of electronic processes and lattice dynamics in diverse classes of correlated quantum systems. This review offers a concise description of the state-of-the-art near-field techniques applied to prototypical correlated quantum materials. We also discuss complementary microscopic and spectroscopic methods which reveal important mesoscopic dynamics of quantum materials at different energy scales.
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Affiliation(s)
- Mengkun Liu
- Department of Physics, Stony Brook University, Stony Brook, NY 11794, USA
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15
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Chen L, Fan J, Tong W, Hu D, Ji Y, Liu J, Zhang L, Pi L, Zhang Y, Yang H. Evolution of the intrinsic electronic phase separation in La 0.6Er 0.1Sr 0.3MnO 3 perovskite. Sci Rep 2016; 6:14. [PMID: 28442764 PMCID: PMC5431341 DOI: 10.1038/s41598-016-0009-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 08/15/2016] [Indexed: 11/19/2022] Open
Abstract
Magnetic and electronic transport properties of perovskite manganite La0.6Er0.1Sr0.3MnO3 have been thoroughly examined through the measurements of magnetization, electron paramagnetic resonance(EPR), and resistivity. It was found that the substitution of Er3+ for La3+ ions introduced the chemical disorder and additional strain in this sample. An extra resonance signal occurred in EPR spectra at high temperatures well above TC gives a strong evidence of electronic phase separation(EPS). The analysis of resistivity enable us to identify the polaronic transport mechanism in the paramagnetic region. At low temperature, a new ferromagnetic interaction generates in the microdomains of Er3+-disorder causing the second increase of magnetization. However, the new ferromagnetic interaction does not improve but decreases electronic transport due to the enhancement of interface resistance among neighboring domains. In view of a really wide temperature region for the EPS existence, this sample provides an ideal platform to uncover the evolution law of different magnetic structures in perovskite manganites.
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Affiliation(s)
- Lili Chen
- Department of Applied Physics, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
| | - Jiyu Fan
- Department of Applied Physics, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China.
| | - Wei Tong
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, 230031, China
| | - Dazhi Hu
- Department of Applied Physics, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
| | - Yanda Ji
- Department of Applied Physics, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
| | - Jindong Liu
- Department of Applied Physics, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
| | - Lei Zhang
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, 230031, China
| | - Li Pi
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, 230031, China
| | - Yuheng Zhang
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, 230031, China
| | - Hao Yang
- Department of Applied Physics, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China.
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Superconductor to Mott insulator transition in YBa2Cu3O7/LaCaMnO3 heterostructures. Sci Rep 2016; 6:33184. [PMID: 27627855 PMCID: PMC5024130 DOI: 10.1038/srep33184] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 08/15/2016] [Indexed: 11/08/2022] Open
Abstract
The superconductor-to-insulator transition (SIT) induced by means such as external magnetic fields, disorder or spatial confinement is a vivid illustration of a quantum phase transition dramatically affecting the superconducting order parameter. In pursuit of a new realization of the SIT by interfacial charge transfer, we developed extremely thin superlattices composed of high Tc superconductor YBa2Cu3O7 (YBCO) and colossal magnetoresistance ferromagnet La0.67Ca0.33MnO3 (LCMO). By using linearly polarized resonant X-ray absorption spectroscopy and magnetic circular dichroism, combined with hard X-ray photoelectron spectroscopy, we derived a complete picture of the interfacial carrier doping in cuprate and manganite atomic layers, leading to the transition from superconducting to an unusual Mott insulating state emerging with the increase of LCMO layer thickness. In addition, contrary to the common perception that only transition metal ions may respond to the charge transfer process, we found that charge is also actively compensated by rare-earth and alkaline-earth metal ions of the interface. Such deterministic control of Tc by pure electronic doping without any hindering effects of chemical substitution is another promising route to disentangle the role of disorder on the pseudo-gap and charge density wave phases of underdoped cuprates.
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Zhu Y, Du K, Niu J, Lin L, Wei W, Liu H, Lin H, Zhang K, Yang T, Kou Y, Shao J, Gao X, Xu X, Wu X, Dong S, Yin L, Shen J. Chemical ordering suppresses large-scale electronic phase separation in doped manganites. Nat Commun 2016; 7:11260. [PMID: 27053071 PMCID: PMC4829688 DOI: 10.1038/ncomms11260] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 03/07/2016] [Indexed: 11/27/2022] Open
Abstract
For strongly correlated oxides, it has been a long-standing issue regarding the role of the chemical ordering of the dopants on the physical properties. Here, using unit cell by unit cell superlattice growth technique, we determine the role of chemical ordering of the Pr dopant in a colossal magnetoresistant (La(1-y)Pr(y))(1-x)Ca(x)MnO3 (LPCMO) system, which has been well known for its large length-scale electronic phase separation phenomena. Our experimental results show that the chemical ordering of Pr leads to marked reduction of the length scale of electronic phase separations. Moreover, compared with the conventional Pr-disordered LPCMO system, the Pr-ordered LPCMO system has a metal-insulator transition that is ∼100 K higher because the ferromagnetic metallic phase is more dominant at all temperatures below the Curie temperature.
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Affiliation(s)
- Yinyan Zhu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Kai Du
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Jiebin Niu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100080, China
| | - Lingfang Lin
- Department of Physics, Southeast University, Nanjing 211189, China
| | - Wengang Wei
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Hao Liu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Hanxuan Lin
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Kai Zhang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Tieying Yang
- Shanghai Synchrotron Radiation Facility (SSRF), Shanghai 201204, China
| | - Yunfang Kou
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Jian Shao
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Xingyu Gao
- Shanghai Synchrotron Radiation Facility (SSRF), Shanghai 201204, China
| | - Xiaoshan Xu
- Department of Physics and Astronom, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - Xiaoshan Wu
- Department of Physics, Nanjing University, Nanjing 211189, China
| | - Shuai Dong
- Department of Physics, Southeast University, Nanjing 211189, China
| | - Lifeng Yin
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Jian Shen
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
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18
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The effect of Ba-site substitution on the magnetic behavior of ordered perovskite RBaMn2O6 (R = rare earth). J SOLID STATE CHEM 2015. [DOI: 10.1016/j.jssc.2015.04.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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19
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Markovich V, Wisniewski A, Szymczak H. Magnetic Properties of Perovskite Manganites and Their Modifications. HANDBOOK OF MAGNETIC MATERIALS 2014. [DOI: 10.1016/b978-0-444-63291-3.00001-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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20
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Mishra DK, Sathe VG, Rawat R, Ganesan V. Enhancement of the ferromagnetic metallic phase fraction by extrinsic disorder in phase separated La(5/8-y)Pr(y)Ca(3/8)MnO3 (y = 0.45) thin film. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:175003. [PMID: 23524465 DOI: 10.1088/0953-8984/25/17/175003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Our study shows that extrinsic disorder plays a decisive role in shaping inhomogeneities at large length scales in phase separated systems. Epitaxial La5/8-yPryCa3/8MnO3 (y = 0.45) thin films grown on SrTiO3, LaAlO3 and NdGaO3 substrates exhibited comparable biaxial strain while showing markedly dissimilar extrinsic disorder. Compressively strained film on LaAlO3 is found to be free from extrinsic disorder and has a robust insulating phase with small phase separation while film grown on SrTiO3 shows huge extrinsic disorder due to the strain relaxation process which invokes phase separation at a large length scale that is sufficient to cross the percolation threshold and cause a metal-insulator transition.
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Affiliation(s)
- Dileep K Mishra
- UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore-452001, India
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21
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Mukherjee A, Cole WS, Woodward P, Randeria M, Trivedi N. Theory of strain-controlled magnetotransport and stabilization of the ferromagnetic insulating phase in manganite thin films. PHYSICAL REVIEW LETTERS 2013; 110:157201. [PMID: 25167302 DOI: 10.1103/physrevlett.110.157201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Indexed: 06/03/2023]
Abstract
We show that applying strain on half-doped manganites makes it possible to tune the system to the proximity of a metal-insulator transition and thereby generate a colossal magnetoresistance (CMR) response. This phase competition not only allows control of CMR in ferromagnetic metallic manganites but can be used to generate CMR response in otherwise robust insulators at half-doping. Further, from our realistic microscopic model of strain and magnetotransport calculations within the Kubo formalism, we demonstrate a striking result of strain engineering that, under tensile strain, a ferromagnetic charge-ordered insulator, previously inaccessible to experiments, becomes stable.
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Affiliation(s)
- Anamitra Mukherjee
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada and Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - William S Cole
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - Patrick Woodward
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Mohit Randeria
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - Nandini Trivedi
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
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22
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Niebieskikwiat D, Sánchez RD. Pinning of elastic ferromagnetic/antiferromagnetic interfaces in phase-separated manganites. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:436001. [PMID: 23032919 DOI: 10.1088/0953-8984/24/43/436001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We present a study of the magnetic properties of the Pr(0.5)Sr(0.5-x)Ca(x)MnO(3) manganite (x = 0.1 and 0.2) in the temperature region where phase separation occurs. This state is characterized by the presence of ferromagnetic (FM) inclusions inside an antiferromagnetic (AFM) matrix. The evolution of the magnetization (M) with magnetic field shows the existence of a critical field, H(C), above which M rapidly increases, indicating a sudden expansion of the FM volume against the AFM one. We analyze this behavior and the response of the magnetic susceptibility at low fields (H < H(C)) in terms of a thermally activated motion of pinned FM/AFM elastic interfaces. The pinning mechanism is likely to be related to the martensitic accommodation strain around the magnetic and structural interfaces. From this analysis we estimate the size of the FM domains and the parameters that characterize the pinning potential.
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Affiliation(s)
- D Niebieskikwiat
- Colegio de Ciencias e Ingeniería, Universidad San Francisco de Quito, Quito, Ecuador.
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23
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Zhou S, Guo Y, Wang C, He L, Zhao J, Shi L. Magnetic phase diagram of nanosized half-doped manganites: role of size reduction. Dalton Trans 2012; 41:7109-14. [PMID: 22565283 DOI: 10.1039/c2dt00029f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The magnetic properties of ~40 nm Nd(0.5)Ca(0.5)MnO(3) and Sm(0.5)Sr(0.5)MnO(3) nanoparticles are investigated by magnetometry and electronic spin resonance (ESR) spectroscopy. It is found that although their bulk counterparts have quite different magnetic properties at low temperatures, both the nanoparticles exhibit very similar magnetic behaviors, where the charge ordered transitions disappear and weak ferromagnetism emerges below about 100 K. A detailed analysis on the magnetic susceptibilities and the ESR linewidths reveals that for the two compounds the size reduction weakens both the ferromagnetic and antiferromagnetic interactions, and converts the long-range charge orderings to short-range ones. Moreover, the strength of the charge ordered correlations is observed to be not much affected by the size reduction. Based on the present results and the previous studies on various nanosized half-doped manganites, the magnetic phase diagram of the half-doped manganites with the particle sizes of ~25-40 nm is established. We find that this diagram is very similar to those for the bulk near half-doped manganites with large quenched disorder, which allows us to propose that the reported exotic phenomena in the nanosized half-doped manganites should be mainly ascribed to surface disorder effect. These results may provide a deeper insight into the role of size reduction on the physics of half-doped manganites.
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Affiliation(s)
- Shiming Zhou
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
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24
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Dhiman I, Das A, Nigam AK, Gasser U. Influence of B-site disorder in La0.5Ca0.5Mn(1 - x)B(x)O3 (B = Fe, Ru, Al and Ga) manganites. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:246006. [PMID: 21628788 DOI: 10.1088/0953-8984/23/24/246006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have investigated the influence of B-site doping on the crystal and magnetic structure in La(0.5)Ca(0.5)Mn(1 - x)B(x)O(3) (B = Fe, Ru, Al and Ga) compounds using neutron diffraction, small angle neutron scattering, magnetization and resistivity techniques. The B-site doped samples are isostructural and possess an orthorhombic structure in the Pnma space group at 300 K. A structural transition from orthorhombic to monoclinic is found to precede the magnetic transition to the CE-type antiferromagnetic state in a few of these samples. On doping with Fe, the charge and orbitally ordered CE-type antiferromagnetic state is suppressed, followed by growth of the ferromagnetic insulating phase in 0.02 ≤ x ≤ 0.06 compounds. At higher Fe doping in x > 0.06, the ferromagnetic state is also suppressed and no evidence of long range magnetic ordering is observed. In Ru doped samples (0.01 ≤ x ≤ 0.05), the ferromagnetic metallic state is favored at T(C)≈200 K and T(MI)≈125 K and no significant change in T(C) and T(MI) as a function of Ru doping is found. In contrast, with non-magnetic Al substitution for 0.01 ≤ x ≤ 0.03, the charge ordered CE-type antiferromagnetic state coexists with the ferromagnetic metallic phase. With further increase in Al doping (0.05 ≤ x ≤ 0.07), both CE-type antiferromagnetic and ferromagnetic phases are gradually suppressed. This behavior is accompanied by the evolution of an A-type antiferromagnetic insulating state. Eventually, at higher Al doping (0.10 ≤ x ≤ 0.13), this phase is also suppressed and the signature of a spin glass like transition is evident in M(T). Likewise, substitution with Ga is observed to induce similar effects to those described for Al doped samples. The presence of short ranged ferromagnetic ordering has been further explored using small angle neutron scattering measurements in a few of the selected samples.
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Affiliation(s)
- Indu Dhiman
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai, India
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25
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Harikrishnan S, Rössler S, Kumar CMN, Xiao Y, Bhat HL, Rössler UK, Steglich F, Wirth S, Elizabeth S. Memory effect in Dy0.5Sr0.5MnO3 single crystals. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:346002. [PMID: 21403267 DOI: 10.1088/0953-8984/22/34/346002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have performed a series of magnetic aging experiments on single crystals of Dy(0.5)Sr(0.5)MnO(3). The results demonstrate striking memory and chaos-like effects in this insulating half-doped perovskite manganite and suggest the existence of strong magnetic relaxation mechanisms of a clustered magnetic state. The spin-glass-like state established below a temperature T(sg)≈ 34 K originates from quenched disorder arising due to the ionic-radii mismatch at the rare earth site. However, deviations from the typical behavior seen in canonical spin glass materials are observed which indicate that the glassy magnetic properties are due to cooperative and frustrated dynamics in a heterogeneous or clustered magnetic state. In particular, the microscopic spin flip time obtained from dynamical scaling near the spin glass freezing temperature is four orders of magnitude larger than microscopic times found in atomic spin glasses. The magnetic viscosity deduced from the time dependence of the zero-field-cooled magnetization exhibits a peak at a temperature T < T(sg) and displays a marked dependence on waiting time in zero field.
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Affiliation(s)
- S Harikrishnan
- Department of Physics, Indian Institute of Science, Bangalore, India
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26
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Pomjakushin VY, Sheptyakov DV, Pomjakushina EV, Conder K, Balagurov AM. Evidence for the strong effect of quenched correlated disorder on phase separation and magnetism in (La(1-y)Pr(y))0.7Ca0.3MnO3. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:115601. [PMID: 21389468 DOI: 10.1088/0953-8984/22/11/115601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
High resolution neutron diffraction shows that the mesoscopic separation into ferromagnetic (FM) and antiferromagnetic (AFM) phases and the FM transition temperature T(C) in the perovskite manganite (La(1-y)Pr(y))(0.7)Ca(0.3)MnO(3) strongly depend on the quenched correlated disorder. The different disorder strengths are achieved by different procedures of the sample synthesis and are quantitatively characterized by the microstrain-type diffraction peak broadening. The system shifts to predominantly a one-phase state with smaller T(C) as the correlated disorder strength is decreased, supporting the viewpoint that the origin of phase separation in the indicated manganite system is the correlated quenched disorder. The ground state of an ultimately chemically homogeneous sample is FM-like containing about 20% of the AFM minority phase. This FM-like state can be readily transformed to the AFM-like one having < 20% of the FM phase by the decrease of the effective charge carrier bandwidth via oxygen isotope substitution.
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Affiliation(s)
- V Yu Pomjakushin
- Laboratory for Neutron Scattering, ETH Zurich and Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.
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27
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Castro EV, Dos Santos JMBL. Substitutional disorder and charge localization in manganites. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:075601. [PMID: 21386393 DOI: 10.1088/0953-8984/22/7/075601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In the manganites RE(1 - x)AE(x)MnO(3) (RE and AE being rare-earth and alkaline-earth elements, respectively) the random distribution of RE(3 + ) and AE(2 + ) induces random, but correlated, shifts of site energies of charge carriers in the Mn sites. We consider a realistic model of this diagonal disorder, in addition to the double-exchange hopping disorder, and investigate the metal-insulator transition as a function of temperature, across the paramagnetic-ferromagnetic line, and as a function of doping x. Contrary to previous results, we find that values of parameters, estimated from the electronic structure of the manganites, are not incompatible with the possibility of a disorder-induced metal to insulator transition accompanying the ferromagnetic to paramagnetic transition at intermediate doping (x ∼ 0.2-0.4). These findings indicate clearly that substitutional disorder has to be considered as an important effect when addressing the colossal magnetoresistance properties of manganites.
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Affiliation(s)
- Eduardo V Castro
- CFP and Departamento de Física, Faculdade de Ciências Universidade do Porto, P-4169-007 Porto, Portugal.
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28
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Nakamura M, Okuyama D, Lee JS, Arima TH, Wakabayashi Y, Kumai R, Kawasaki M, Tokura Y. Magnetically tunable metal-insulator superlattices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2010; 22:500-504. [PMID: 20217742 DOI: 10.1002/adma.200902734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Affiliation(s)
- Masao Nakamura
- Cross-Correlated Materials Research Group, Advanced Science Institute, RIKEN 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
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29
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Wagh AA, Kumar PSA, Bhat HL, Elizabeth S. An investigation of first-order transition across charge ordered and ferromagnetic phases in Gd(0.5)Sr(0.5)MnO3 single crystals by magnetic and magnetotransport studies. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:026005. [PMID: 21386269 DOI: 10.1088/0953-8984/22/2/026005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Gadolinium strontium manganite single crystals of the composition Gd(0.5)Sr(0.5)MnO(3) were grown using the optical float zone method. We report here the magnetic and magnetotransport properties of these crystals. A large magnetoresistance ∼10(9)% was observed at 45 K under the application of a 110 kOe field. We have observed notable thermomagnetic anomalies such as open hysteresis loops across the broadened first-order transition between the charge order insulator and the ferromagnetic metallic phase while traversing the magnetic field-temperature (H-T) plane isothermally or isomagnetically. In order to discern the cause of these observed anomalies, the H-T phase diagram for Gd(0.5)Sr(0.5)MnO(3) is formulated using the magnetization-field (M-H), magnetization-temperature (M-T) and resistance-temperature (R-T) measurements. The temperature dependence of the critical field (i.e. H(up), the field required for transformation to the ferromagnetic metallic phase) is non-monotonic. We note that the non-monotonic variation of the supercooling limit is anomalous according to the classical concepts of the first-order phase transition. Accordingly, H(up) values below ∼20 K are unsuitable to represent the supercooling limit. It is possible that the nature of the metastable states responsible for the observed open hysteresis loops is different from that of the supercooled ones.
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Affiliation(s)
- Aditya A Wagh
- Department of Physics, Indian Institute of Science, C V Raman Avenue, Bangalore 560012, India.
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30
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May SJ, Ryan PJ, Robertson JL, Kim JW, Santos TS, Karapetrova E, Zarestky JL, Zhai X, te Velthuis SGE, Eckstein JN, Bader SD, Bhattacharya A. Enhanced ordering temperatures in antiferromagnetic manganite superlattices. NATURE MATERIALS 2009; 8:892-7. [PMID: 19838186 DOI: 10.1038/nmat2557] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2009] [Accepted: 09/21/2009] [Indexed: 05/10/2023]
Abstract
The disorder inherent to doping by cation substitution in the complex oxides can have profound effects on collective-ordered states. Here, we demonstrate that cation-site ordering achieved through digital-synthesis techniques can dramatically enhance the antiferromagnetic ordering temperatures of manganite films. Cation-ordered (LaMnO3)m/(SrMnO3)2m superlattices show Néel temperatures (TN) that are the highest of any La(1-x)Sr(x)MnO3 compound, approximately 70 K greater than compositionally equivalent randomly doped La(1/3)Sr(2/3)MnO3. The antiferromagnetic order is A-type, consisting of in-plane double-exchange-mediated ferromagnetic sheets coupled antiferromagnetically along the out-of-plane direction. Through synchrotron X-ray scattering, we have discovered an in-plane structural modulation that reduces the charge itinerancy and hence the ordering temperature within the ferromagnetic sheets, thereby limiting TN. This modulation is mitigated and driven to long wavelengths by cation ordering, enabling the higher TN values of the superlattices. These results provide insight into how cation-site ordering can enhance cooperative behaviour in oxides through subtle structural phenomena.
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Affiliation(s)
- S J May
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
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31
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Effect of sodium substitution on the structural, magnetic and magnetocaloric properties of La0.5Ca0.5MnO3 perovskite manganites. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.phpro.2009.11.052] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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32
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Dong S, Yu R, Liu JM, Dagotto E. Striped multiferroic phase in double-exchange model for quarter-doped manganites. PHYSICAL REVIEW LETTERS 2009; 103:107204. [PMID: 19792340 DOI: 10.1103/physrevlett.103.107204] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2009] [Indexed: 05/28/2023]
Abstract
The phase diagram of quarter-hole-doped perovskite manganites is investigated using the double-exchange model. An exotic striped type-II multiferroic phase, where 25% of the nearest-neighbor spin couplings are orthogonal to each other, is found in the narrow-bandwidth region. Comparing with the spiral-spin ordering phase of undoped manganites, the multiferroic Curie temperature of the new phase is estimated to be approximately 4 times higher, while the ferroelectric polarization is similar in magnitude. Our study provides a path for noncollinear spin multiferroics based on electronic self-organization, different from the traditional approach based on superexchange frustration.
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Affiliation(s)
- Shuai Dong
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
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33
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García-Fernández M, Staub U, Bodenthin Y, Scagnoli V, Pomjakushin V, Lovesey SW, Mirone A, Herrero-Martín J, Piamonteze C, Pomjakushina E. Orbital order at Mn and O sites and absence of Zener polaron formation in manganites. PHYSICAL REVIEW LETTERS 2009; 103:097205. [PMID: 19792826 DOI: 10.1103/physrevlett.103.097205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Indexed: 05/28/2023]
Abstract
We report the doping dependence of the ground state of A-site ordered manganites below and above half doping. Energy and polarization dependence of the orbital reflection, taken by resonant soft-x-ray powder diffraction, at both Mn L(2,3) and O K edges, provides direct evidence for orbital order at Mn(3+) and oxygen sites and absence of Zener polaron formation. For x > or = 0.2 anomalous melting of the orbital order is observed, which is coupled neither to magnetic ordering nor to a structural transition, indicating a two-dimensional character of the interactions.
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Affiliation(s)
- M García-Fernández
- Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
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34
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Manganite charge and orbitally ordered and disordered states probed by Fe substitution into Mn site in , and (, Gd, Sm, Nd, Pr, La). J SOLID STATE CHEM 2009. [DOI: 10.1016/j.jssc.2009.05.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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35
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Daoud-Aladine A, Perca C, Pinsard-Gaudart L, Rodríguez-Carvajal J. Zener polaron ordering variants induced by A-site ordering in half-doped manganites. PHYSICAL REVIEW LETTERS 2008; 101:166404. [PMID: 18999692 DOI: 10.1103/physrevlett.101.166404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Revised: 05/19/2008] [Indexed: 05/27/2023]
Abstract
We have studied the magnetism of the half-doped charge ordered manganite YBaMn2O6. A formation of ferromagnetic plaquettes of four Mn atoms in the charge ordered phase below T_{CO} approximately 480 K is inferred from high temperature magnetic susceptibility data and the magnetic structure, as determined by neutron powder diffraction at T=1.5 K. The results indicate that new fourfold Mn paramagnetic units form between T_{N}<T<T_{CO}, and that they order in a noncollinear mode below T_{N}=190 K. The magnetism of YBaMn2O6 is consistent with what is expected from the Zener polarons ordering picture of the charge ordering phenomenon in manganites [A. Daoud-Aladine, Phys. Rev. Lett. 89, 097205 (2002)10.1103/PhysRevLett.89.097205].
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Affiliation(s)
- A Daoud-Aladine
- ISIS Facility, Rutherford Appleton Laboratory-CCLRC, Chilton, Didcot, Oxfordshire, United Kingdom
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36
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Harikrishnan S, Naveen Kumar CM, Bhat HL, Elizabeth S, Rößler UK, Dörr K, Rößler S, Wirth S. Investigations on the spin-glass state in Dy(0.5)Sr(0.5)MnO(3) single crystals through structural, magnetic and thermal properties. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2008; 20:275234. [PMID: 21694395 DOI: 10.1088/0953-8984/20/27/275234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Single crystals of Dy(0.5)Sr(0.5)MnO(3) are grown using the optical floating zone technique, and their structural, magnetic, transport and thermal properties have been investigated. Magnetization measurements under field-cooled and zero-field-cooled conditions display irreversibility below 35 K. The magnetization does not saturate up to fields of 5 T in the temperature range 5-350 K. AC susceptibility shows a cusp around 32 K that shifts to higher temperature with increasing frequency. This frequency dependence of the peak temperature follows a critical slowing down with exponent zν = 3.6. Electrical resistivity shows insulating behavior, and the application of magnetic fields up to 10 T does not change this qualitative behavior. However, a marked negative magnetoresistance is observed in the paramagnetic phase reaching 80% at 70 K and 10 T. The observed resistivity behavior does not obey an activated type of conduction. These features are characteristic of spin-glass behavior in this half-doped insulating manganite. It is argued that the spin-glass-like state originates from the A-site disorder, which in turn results from the random distribution of cations with different ionic radii. Specific-heat measurements reveal a sizable linear contribution at low temperature that may be associated with the glassy magnetic ordering and a Schottky-like anomaly in a wide temperature range between 8 and 40 K. The distribution of Schottky levels is explained by the inhomogeneity of the molecular field in the spin-glass state that leads to variable splitting of the Kramers ground-state doublets in Dy(3+).
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Affiliation(s)
- S Harikrishnan
- Department of Physics, Indian Institute of Science, C V Raman Avenue, Bangalore 560012, India
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Bhattacharya A, May SJ, te Velthuis SGE, Warusawithana M, Zhai X, Jiang B, Zuo JM, Fitzsimmons MR, Bader SD, Eckstein JN. Metal-insulator transition and its relation to magnetic structure in (LaMnO3)2n/(SrMnO3)n superlattices. PHYSICAL REVIEW LETTERS 2008; 100:257203. [PMID: 18643699 DOI: 10.1103/physrevlett.100.257203] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2007] [Indexed: 05/26/2023]
Abstract
Superlattices of (LaMnO3){2n}/(SrMnO3){n} (1<or=n<or=5), composed of the gapped insulators LaMnO3 and SrMnO3, undergo a metal-insulator transition as a function of n, being metallic for n<or=2 and insulating for n>or=3. Measurements of transport, magnetization, and polarized neutron reflectivity reveal that the ferromagnetism is relatively uniform in the metallic state, and is strongly modulated in the insulating state, being high in LaMnO3 and suppressed in SrMnO3. The modulation is consistent with a Mott transition driven by the proximity between the (LaMnO3)/(SrMnO3) interfaces. The insulating state for n>or=3 obeys variable range hopping at low temperatures. We suggest that this is due to states at the Fermi level that emerge at the (LaMnO3)/(SrMnO3) interfaces and are localized by disorder.
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Affiliation(s)
- A Bhattacharya
- Materials Science Division and Argonne National Laboratory, Argonne, Illinois 60439, USA.
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Kumar S, Kampf AP. Combined effect of bond and potential disorder in half-doped manganites. PHYSICAL REVIEW LETTERS 2008; 100:076406. [PMID: 18352580 DOI: 10.1103/physrevlett.100.076406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Indexed: 05/26/2023]
Abstract
We analyze the effects of both bond and potential disorder in the vicinity of a first-order metal insulator transition in a two-band model for manganites using a real-space Monte Carlo method. Our results reveal a novel charge-ordered state coexisting with spin-glass behavior. We provide the basis for understanding the phase diagrams of half-doped manganites, and contrast the effects of bond and potential disorder and the combination of both.
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Affiliation(s)
- Sanjeev Kumar
- Theoretical Physics III, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, D-86135 Augsburg, Germany
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Pradhan K, Mukherjee A, Majumdar P. Distinct effects of homogeneous weak disorder and dilute strong scatterers on phase competition in manganites. PHYSICAL REVIEW LETTERS 2007; 99:147206. [PMID: 17930717 DOI: 10.1103/physrevlett.99.147206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Indexed: 05/25/2023]
Abstract
We study the two orbital double-exchange model in two dimensions including antiferromagnetic (AFM) superexchange, Jahn-Teller coupling, and substitutional disorder. At hole doping x = 0.5 we focus on phase competition between the ferromagnetic metal (FMM) and the charge-ordered (CO) and orbital-ordered (OO) CE state and compare the impact of weak homogeneous disorder to that of a low density of strong scatterers. Even moderate homogeneous disorder suppresses the CE-CO-OO phase and leads to a glass with nanoscale correlations, while dilute strong scatterers of comparable strength convert the CE-CO-OO phase to a phase separated state with ferromagnetic metal and AFM-CO-OO clusters.
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Zhang J, Ye F, Sha H, Dai P, Fernandez-Baca JA, Plummer EW. Magnons in ferromagnetic metallic manganites. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2007; 19:315204. [PMID: 21694105 DOI: 10.1088/0953-8984/19/31/315204] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Ferromagnetic (FM) manganites, a group of likely half-metallic oxides, are of special interest not only because they are a testing ground for the classical double-exchange interaction mechanism for the 'colossal' magnetoresistance, but also because they exhibit an extraordinary arena of emergent phenomena. These emergent phenomena are related to the complexity associated with strong interplay between charge, spin, orbital, and lattice. In this review, we focus on the use of inelastic neutron scattering to study the spin dynamics, mainly the magnon excitations in this class of FM metallic materials. In particular, we discuss the unusual magnon softening and damping near the Brillouin zone boundary in relatively narrow-band compounds with strong Jahn-Teller lattice distortion and charge-orbital correlations. The anomalous behaviours of magnons in these compounds indicate the likelihood of cooperative excitations involving spin and lattice as well as orbital degrees of freedom.
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Affiliation(s)
- Jiandi Zhang
- Department of Physics, Florida International University, Miami, FL 33199, USA
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41
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Taskin AA, Ando Y. Peculiar ferrimagnetism associated with charge order in layered perovskite GdBaMn2O5.0. PHYSICAL REVIEW LETTERS 2007; 98:207201. [PMID: 17677732 DOI: 10.1103/physrevlett.98.207201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2007] [Indexed: 05/16/2023]
Abstract
The magnetic properties of GdBaMn2O5.0, which exhibits charge ordering, are studied from 2 to 400 K using single crystals. In a small magnetic field applied along the easy axis, the magnetization M shows a temperature-induced reversal which is sometimes found in ferrimagnets. In a large magnetic field, on the other hand, a sharp change in the slope of M(T) coming from an unusual turnabout of the magnetization of the Mn sublattices is observed. Those observations are essentially explained by a molecular field theory which highlights the role of delicate magnetic interactions between Gd3+ ions and the antiferromagnetically coupled Mn2+/Mn3+ sublattices.
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Affiliation(s)
- A A Taskin
- Central Research Institute of Electric Power Industry, Komae, Tokyo 201-8511, Japan
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Wu W, Israel C, Hur N, Park S, Cheong SW, de Lozanne A. Magnetic imaging of a supercooling glass transition in a weakly disordered ferromagnet. NATURE MATERIALS 2006; 5:881-6. [PMID: 17028576 DOI: 10.1038/nmat1743] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2006] [Accepted: 08/25/2006] [Indexed: 05/12/2023]
Abstract
Spin glasses are founded in the frustration and randomness of microscopic magnetic interactions. They are non-ergodic systems where replica symmetry is broken. Although magnetic glassy behaviour has been observed in many colossal magnetoresistive manganites, there is no consensus that they are spin glasses. Here, an intriguing glass transition in (La,Pr,Ca)MnO3 is imaged using a variable-temperature magnetic force microscope. In contrast to the speculated spin-glass picture, our results show that the observed static magnetic configuration seen below the glass-transition temperature arises from the cooperative freezing of the first-order antiferromagnetic (charge ordered) to ferromagnetic transition. Our data also suggest that accommodation strain is important in the kinetics of the phase transition. This cooperative freezing idea has been applied to structural glasses including window glasses and supercooled liquids, and may be applicable across many systems to any first-order phase transition occurring on a complex free-energy landscape.
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Affiliation(s)
- Weida Wu
- Department of Physics, University of Texas, Austin, Texas 78712, USA
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Moshnyaga V, Sudheendra L, Lebedev OI, Köster SA, Gehrke K, Shapoval O, Belenchuk A, Damaschke B, van Tendeloo G, Samwer K. A-site ordering versus electronic inhomogeneity in colossally magnetoresistive manganite films. PHYSICAL REVIEW LETTERS 2006; 97:107205. [PMID: 17025850 DOI: 10.1103/physrevlett.97.107205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2005] [Indexed: 05/12/2023]
Abstract
Epitaxial La(3/4)Ca(1/4)MnO3/MgO(100) (LCMO) thin film shows an unusual rhombohedral (R-3c) structure with a new perovskite superstructure at room temperature due to the CE-type ordering of La and Ca with modulation vector q=1/4[011]. A-site ordered film was found to be electronically homogeneous down to the 1 nm scale as revealed by scanning tunnelling microscopy/spectroscopy. In contrast, orthorhombic and A-site disordered LCMO demonstrate a mesoscopic phase separation far below the Curie temperature (TC). Unique La/Ca ordering compensates the cation mismatch stress within one supercell, a(S) approximately 1.55 nm, and enhances the electronic homogeneity. The phase separation does not seem to be a unique mechanism for the colossal magnetoresistance (CMR) as very large CMR approximately 500% was also observed in A-site ordered films.
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Affiliation(s)
- V Moshnyaga
- Erstes Physikalisches Institut, Universität Göttingen, Friedrich-Hund-Platz 1, D-37077 Göttingen, Germany
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Ye F, Dai P, Fernandez-Baca JA, Sha H, Lynn JW, Kawano-Furukawa H, Tomioka Y, Tokura Y, Zhang J. Evolution of spin-wave excitations in ferromagnetic metallic manganites. PHYSICAL REVIEW LETTERS 2006; 96:047204. [PMID: 16486884 DOI: 10.1103/physrevlett.96.047204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2005] [Indexed: 05/06/2023]
Abstract
Neutron scattering results are presented for spin-wave excitations of three ferromagnetic metallic A1-xA'xMnO3 manganites (where A and A' are rare- and alkaline-earth-metal ions), which when combined with previous work elucidate the systematics of the interactions as a function of carrier concentration x, on-site disorder, and strength of the lattice distortion. The long-wavelength spin dynamics show only a very weak dependence across the series. The ratio of fourth to first neighbor exchange (J4/J1) that controls the zone boundary magnon softening changes systematically with x, but does not depend on the other parameters. None of the prevailing models can account for these behaviors.
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Affiliation(s)
- F Ye
- Center for Neutron Scattering, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393, USA
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Kawasaki Y, Minami T, Kishimoto Y, Ohno T, Zenmyo K, Kubo H, Nakajima T, Ueda Y. Phase separation in A-site-ordered perovskite manganite LaBaMn2O6 probed by 139La and 55Mn NMR. PHYSICAL REVIEW LETTERS 2006; 96:037202. [PMID: 16486760 DOI: 10.1103/physrevlett.96.037202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2005] [Indexed: 05/06/2023]
Abstract
139La- and 55Mn-NMR spectra demonstrate that the ground state of the A-site-ordered perovskite manganite LaBaMn2O6 is a spatial mixture of the ferromagnetic and antiferromagnetic regions, which are assigned to the metallic and the insulating charge ordered state, respectively. This exotic coexisting state appears below 200 K via a first-order-like formation of the antiferromagnetic charge ordered state inside the ferromagnetic metal one. The Mn spin-spin relaxation rate indicates that the ferromagnetic region coexisting with the antiferromagnetic one in LaBaMn2O6 is identical to the bulk ferromagnetic metal phase of the disordered form La0.5Ba0.5MnO3 in spite of the absence of A-site disorder. This suggests a mesoscopic rather than nanoscopic nature of the ferromagnetic region in LaBaMn2O6.
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Affiliation(s)
- Y Kawasaki
- Department of Physics, Faculty of Engineering, Tokushima University, Tokushima 770-8506, Japan
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Kumar S, Majumdar P. Insulator-metal phase diagram of the optimally doped manganites from the disordered Holstein-double exchange model. PHYSICAL REVIEW LETTERS 2006; 96:016602. [PMID: 16486493 DOI: 10.1103/physrevlett.96.016602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2004] [Revised: 08/29/2005] [Indexed: 05/06/2023]
Abstract
We study the Holstein-double exchange model in three dimensions in the presence of substitutional disorder. Using a new Monte Carlo technique we establish the phase diagram of the clean model and then focus on the effect of varying electron-phonon coupling and disorder at fixed electron density. We demonstrate how extrinsic disorder controls the interplay of lattice polaron effects and spin fluctuations and leads to widely varying regimes in transport. Our results on the disorder dependence of the ferromagnetic T(C) and metal-insulator transitions bear direct comparison to data on the "optimally doped," x = 0.3-0.4, manganites. We highlight disorder induced polaron formation as a key effect in these materials, organize a wide variety of data into a simple "global phase diagram," and make several experimental predictions.
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Affiliation(s)
- Sanjeev Kumar
- Harish-Chandra Research Institute, Chhatnag Road, Jhusi, Allahabad 211 019, India
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Deisenhofer J, Braak D, Krug von Nidda HA, Hemberger J, Eremina RM, Ivanshin VA, Balbashov AM, Jug G, Loidl A, Kimura T, Tokura Y. Observation of a griffiths phase in paramagnetic La1-xSrxMnO3. PHYSICAL REVIEW LETTERS 2005; 95:257202. [PMID: 16384501 DOI: 10.1103/physrevlett.95.257202] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Indexed: 05/05/2023]
Abstract
We report on the discovery of a novel triangular phase regime in the system La1-xSrxMnO3 by means of electron spin resonance and magnetic susceptibility measurements. This phase is characterized by the coexistence of ferromagnetic entities within the globally paramagnetic phase far above the magnetic ordering temperature. The nature of this phase can be understood in terms of Griffiths singularities arising due to the presence of correlated quenched disorder in the orthorhombic phase.
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Affiliation(s)
- J Deisenhofer
- EP V, Center for Electronic Correlations and Magnetism, University of Augsburg, 86135 Augsburg, Germany
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Dabrowski B, Caspi E, Kolesnik S, Chmaissem O, Mais J, Jorgensen J. Synthesis, structure, and magnetic properties of SrMn1−xGaxO3−δ (x=0–0.5) perovskites. J SOLID STATE CHEM 2005. [DOI: 10.1016/j.jssc.2005.08.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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