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Shimura Y, Wörl A, Sundermann M, Tsuda S, Adroja DT, Bhattacharyya A, Strydom AM, Hillier AD, Pratt FL, Gloskovskii A, Severing A, Onimaru T, Gegenwart P, Takabatake T. Antiferromagnetic Correlations in Strongly Valence Fluctuating CeIrSn. PHYSICAL REVIEW LETTERS 2021; 126:217202. [PMID: 34114835 DOI: 10.1103/physrevlett.126.217202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 04/29/2021] [Indexed: 06/12/2023]
Abstract
CeIrSn with a quasikagome Ce lattice in the hexagonal basal plane is a strongly valence fluctuating compound, as we confirm by hard x-ray photoelectron spectroscopy and inelastic neutron scattering, with a high Kondo temperature of T_{K}∼480 K. We report a negative in-plane thermal expansion α/T below 2 K, which passes through a broad minimum near 0.75 K. Volume and a-axis magnetostriction for B∥a are markedly negative at low fields and change sign before a sharp metamagnetic anomaly at 6 T. These behaviors are unexpected for Ce-based intermediate valence systems, which should feature positive expansivity. Rather they point towards antiferromagnetic correlations at very low temperatures. This is supported by muon spin relaxation measurements down to 0.1 K, which provide microscopic evidence for a broad distribution of internal magnetic fields. Comparison with isostructural CeRhSn suggests that these antiferromagnetic correlations emerging at T≪T_{K} result from geometrical frustration.
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Affiliation(s)
- Y Shimura
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima 739-8530, Japan
| | - A Wörl
- Experimental Physics VI, Center for Electronic Correlations and Magnetism, University of Augsburg, 86159 Augsburg, Germany
| | - M Sundermann
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
- Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany
| | - S Tsuda
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima 739-8530, Japan
| | - D T Adroja
- ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot Oxon OX11 0QX, United Kingdom
- Highly Correlated Matter Research Group, Physics Department, University of Johannesburg, PO Box 524, Auckland Park 2006, South Africa
| | - A Bhattacharyya
- Department of Physics, Ramakrishna Mission Vivekananda Educational and Research Institute, Belur Math, Howrah 711202, West Bengal, India
| | - A M Strydom
- Highly Correlated Matter Research Group, Physics Department, University of Johannesburg, PO Box 524, Auckland Park 2006, South Africa
| | - A D Hillier
- ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot Oxon OX11 0QX, United Kingdom
| | - F L Pratt
- ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot Oxon OX11 0QX, United Kingdom
| | - A Gloskovskii
- Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany
| | - A Severing
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
- Institute of Physics II, University of Cologne, 50937 Cologne, Germany
| | - T Onimaru
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima 739-8530, Japan
| | - P Gegenwart
- Experimental Physics VI, Center for Electronic Correlations and Magnetism, University of Augsburg, 86159 Augsburg, Germany
| | - T Takabatake
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima 739-8530, Japan
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Das D, Gnida D, Bochenek Ł, Rudenko A, Daszkiewicz M, Kaczorowski D. Magnetic field driven complex phase diagram of antiferromagnetic heavy-fermion superconductor Ce 3PtIn 11. Sci Rep 2018; 8:16703. [PMID: 30420684 PMCID: PMC6232155 DOI: 10.1038/s41598-018-34991-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 10/29/2018] [Indexed: 11/09/2022] Open
Abstract
We present the results of our comprehensive investigation on the antiferromagnetic heavy-fermion superconductor Ce3PtIn11 carried out by means of electrical transport, heat capacity and ac magnetic susceptibility measurements, performed on single-crystalline specimens down to 50 mK in external magnetic fields up to 9 T. Our experimental results elucidate a complex magnetic field - temperature phase diagram which contains both first- and second-order field-induced magnetic transitions and highlights the emergence of field stabilized phases. Remarkably, a prominent metamagnetic transition was found to occur at low temperatures and strong magnetic fields. In turn, the results obtained in the superconducting phase of Ce3PtIn11 corroborate an unconventional nature of Cooper pairs formed by heavy quasiparticles. The compound is an almost unique example of a heavy fermion system in which superconductivity may coexist microscopically with magnetically ordered state.
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Affiliation(s)
- Debarchan Das
- Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P. O. Box 1410, 50-950, Wrocław, Poland
| | - Daniel Gnida
- Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P. O. Box 1410, 50-950, Wrocław, Poland
| | - Łukasz Bochenek
- Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P. O. Box 1410, 50-950, Wrocław, Poland
| | - Andriy Rudenko
- Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P. O. Box 1410, 50-950, Wrocław, Poland
| | - Marek Daszkiewicz
- Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P. O. Box 1410, 50-950, Wrocław, Poland
| | - Dariusz Kaczorowski
- Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P. O. Box 1410, 50-950, Wrocław, Poland.
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Küchler R, Wörl A, Gegenwart P, Berben M, Bryant B, Wiedmann S. The world's smallest capacitive dilatometer, for high-resolution thermal expansion and magnetostriction in high magnetic fields. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:083903. [PMID: 28863703 DOI: 10.1063/1.4997073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
For the characterization of novel quantum phases of matter, it is often required to study materials under multi-extreme conditions, in particular down to very low temperatures and in very high magnetic fields. We developed the world's smallest high-resolution capacitive dilatometer suitable for temperatures down to 10 mK and usage in high magnetic fields up to 37.5 T. Despite the extreme miniaturization, the capacitive dilatometer can resolve length changes down to 0.01 Å. This is an unprecedented resolution in a capacitive dilatometer of this compact size. Many cryogenic devices have limited space. Due to the extremely reduced cell size (3 cm3, 12 g), implementation or new applications in many of these sample space lacking devices are now possible. As an important example, the minute device can now be rotated in any standard cryostat, including dilution refrigerators or the commercial physical property measurement system. The present super compact design provides also for high resolution thermal expansion and magnetostriction measurements in a 15.2 mm diameter tube, enabling its use in the 32 mm bore, 37.5 T Bitter magnet at the High Field Magnet Laboratory in Nijmegen down to a temperature of 300 mK.
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Affiliation(s)
- R Küchler
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer St. 40, 01187 Dresden, Germany
| | - A Wörl
- Experimental Physics VI, Center for Electronic Correlations and Magnetism, University of Augsburg, Universitätsstrasse 2, 86135 Augsburg, Germany
| | - P Gegenwart
- Experimental Physics VI, Center for Electronic Correlations and Magnetism, University of Augsburg, Universitätsstrasse 2, 86135 Augsburg, Germany
| | - M Berben
- High Field Magnet Laboratory (HFML-EMFL) and Institute for Molecules and Materials, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - B Bryant
- High Field Magnet Laboratory (HFML-EMFL) and Institute for Molecules and Materials, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - S Wiedmann
- High Field Magnet Laboratory (HFML-EMFL) and Institute for Molecules and Materials, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
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Gegenwart P. Grüneisen parameter studies on heavy fermion quantum criticality. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2016; 79:114502. [PMID: 27710924 DOI: 10.1088/0034-4885/79/11/114502] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The Grüneisen parameter, experimentally determined from the ratio of thermal expansion to specific heat, quantifies the pressure dependence of characteristic energy scales of matter. It is highly enhanced for Kondo lattice systems, whose properties are strongly dependent on the pressure sensitive antiferromagnetic exchange interaction between f- and conduction electrons. In this review, we focus on the divergence of the Grüneisen parameter and its magnetic analogue, the adiabatic magnetocaloric effect, for heavy-fermion metals near quantum critical points. We compare experimental results with current theoretical models, including the effect of strong geometrical frustration. We also discuss the possibility of using materials with the divergent magnetic Grüneisen parameter for adiabatic demagnetization cooling to very low temperatures.
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Affiliation(s)
- Philipp Gegenwart
- EP VI, Center for Electronic Correlations and Magnetism, Institute of Physics, Augsburg University, 86159 Augsburg, Germany
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Steglich F, Wirth S. Foundations of heavy-fermion superconductivity: lattice Kondo effect and Mott physics. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2016; 79:084502. [PMID: 27376190 DOI: 10.1088/0034-4885/79/8/084502] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This article overviews the development of heavy-fermion superconductivity, notably in such rare-earth-based intermetallic compounds which behave as Kondo-lattice systems. Heavy-fermion superconductivity is of unconventional nature in the sense that it is not mediated by electron-phonon coupling. Rather, in most cases the attractive interaction between charge carriers is apparently magnetic in origin. Fluctuations associated with an antiferromagnetic (AF) quantum critical point (QCP) play a major role. The first heavy-fermion superconductor CeCu2Si2 turned out to be the prototype of a larger group of materials for which the underlying, often pressure-induced, AF QCP is likely to be of a three-dimensional (3D) spin-density-wave (SDW) variety. For UBe13, the second heavy-fermion superconductor, a magnetic-field-induced 3D SDW QCP inside the superconducting phase can be conjectured. Such a 'conventional', itinerant QCP can be well understood within Landau's paradigm of order-parameter fluctuations. In contrast, the low-temperature normal-state properties of a few heavy-fermion superconductors are at odds with the Landau framework. They are characterized by an 'unconventional', local QCP which may be considered a zero-temperature 4 f-orbital selective Mott transition. Here, as concluded for YbRh2Si2, the breakdown of the Kondo effect concurring with the AF instability gives rise to an abrupt change of the Fermi surface. Very recently, superconductivity was discovered for this compound at ultra-low temperatures. Therefore, YbRh2Si2 along with CeRhIn5 under pressure provide a natural link between the large group of about fifty low-temperature heavy-fermion superconductors and other families of unconventional superconductors with substantially higher T c, e.g. the doped Mott insulators of the perovskite-type cuprates and the organic charge-transfer salts.
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Affiliation(s)
- Frank Steglich
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany. Center for Correlated Matter, Zhejiang University, Hangzhou, Zhejiang 310058, People's Republic of China. Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
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Küchler R, Stingl C, Gegenwart P. A uniaxial stress capacitive dilatometer for high-resolution thermal expansion and magnetostriction under multiextreme conditions. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:073903. [PMID: 27475567 DOI: 10.1063/1.4958957] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Thermal expansion and magnetostriction are directional dependent thermodynamic quantities. For the characterization of novel quantum phases of matter, it is required to study materials under multi-extreme conditions, in particular, down to very low temperatures, in very high magnetic fields or under high pressure. We developed a miniaturized capacitive dilatometer suitable for temperatures down to 20 mK and usage in high magnetic fields, which exerts a large spring force between 40 to 75 N on the sample. This corresponds to a uniaxial stress up to 3 kbar for a sample with cross section of (0.5 mm)(2). We describe design and performance test of the dilatometer which resolves length changes with high resolution of 0.02 Å at low temperatures. The miniaturized device can be utilized in any standard cryostat, including dilution refrigerators or the commercial physical property measurement system.
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Affiliation(s)
- R Küchler
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany
| | - C Stingl
- Experimental Physics VI, Center for Electronic Correlations and Magnetism, University of Augsburg, Universitätsstrasse 2, 86135 Augsburg, Germany
| | - P Gegenwart
- Experimental Physics VI, Center for Electronic Correlations and Magnetism, University of Augsburg, Universitätsstrasse 2, 86135 Augsburg, Germany
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Küchler R, Bauer T, Brando M, Steglich F. A compact and miniaturized high resolution capacitance dilatometer for measuring thermal expansion and magnetostriction. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:095102. [PMID: 23020414 DOI: 10.1063/1.4748864] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We describe the design, construction, calibration, and two different applications of a miniature capacitance dilatometer. The device is suitable for thermal expansion and magnetostriction measurements from 300 K down to about 25 mK, with a resolution of 0.02 Å at low temperatures. The main body of the dilatometer is fabricated from a single block of a Be-Cu alloy by electrical discharge milling. This creates an extremely compact high-resolution measuring cell. We have successfully tested and operated dilatometers of this new type with the commonly used physical property measurement system by quantum design, as well as with several other cryogenic refrigeration systems down to 25 mK and in magnetic fields up to 20 T. Here, the capacitance is measured with a commercially available capacitance bridge. Using a piezoelectric rotator from Attocube Systems, the cell can be rotated at T = 25 mK inside of an inner vacuum chamber of 40 mm diameter. The miniaturized design for the one-axis rotation setup allows a rotation of 360°.
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Affiliation(s)
- R Küchler
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany
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Okane T, Ohkochi T, Takeda Y, Fujimori SI, Yasui A, Saitoh Y, Yamagami H, Fujimori A, Matsumoto Y, Sugi M, Kimura N, Komatsubara T, Aoki H. 4f-derived Fermi surfaces of CeRu2(Si1-xGex)2 near the quantum critical point: resonant soft-X-ray ARPES study. PHYSICAL REVIEW LETTERS 2009; 102:216401. [PMID: 19519117 DOI: 10.1103/physrevlett.102.216401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2008] [Indexed: 05/27/2023]
Abstract
Angle-resolved photoelectron spectroscopy in the Ce 3d-->4f excitation region was measured for the paramagnetic state of CeRu2Si2, CeRu2(Si0.82Ge0.18)2, and LaRu2Si2 to investigate the changes of the 4f electron Fermi surfaces around the quantum critical point. While the difference of the Fermi surfaces between CeRu2Si2 and LaRu2Si2 was experimentally confirmed, a strong 4f-electron character was observed in the band structures and the Fermi surfaces of CeRu2Si2 and CeRu2(Si0.82Ge0.18)2, consequently indicating a delocalized nature of the 4f electrons in both compounds. The absence of Fermi surface reconstruction across the critical composition suggests that SDW quantum criticality is more appropriate than local quantum criticality in CeRu2(Si1-xGex)2.
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Affiliation(s)
- T Okane
- Synchrotron Radiation Research Center, Japan Atomic Energy Agency, Hyogo 679-5148, Japan.
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Tokiwa Y, Radu T, Geibel C, Steglich F, Gegenwart P. Divergence of the magnetic Grüneisen ratio at the field-induced quantum critical point in YbRh2Si2. PHYSICAL REVIEW LETTERS 2009; 102:066401. [PMID: 19257612 DOI: 10.1103/physrevlett.102.066401] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2008] [Indexed: 05/27/2023]
Abstract
The heavy-fermion metal YbRh2Si2 is studied by low-temperature magnetization M(T) and specific-heat C(T) measurements at magnetic fields close to the quantum critical point (H_{c}=0.06 T, H perpendicularc). Upon approaching the instability, dM/dT is more singular than C(T), leading to a divergence of the magnetic Grüneisen ratio Gamma_{mag}=-(dM/dT)/C. Within the Fermi-liquid regime, Gamma_{mag}=-G_{r}(H-H_{c};{fit}) with G_{r}=-0.30+/-0.01 and H_{c};{fit}=(0.065+/-0.005) T which is consistent with scaling behavior of the specific-heat coefficient in YbRh2(Si0.95Ge0.05)_{2}. The field dependence of dM/dT indicates an inflection point of the entropy as a function of magnetic field upon passing the line T;{ small star, filled}(H) previously observed in Hall and thermodynamic measurements.
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Affiliation(s)
- Y Tokiwa
- Max-Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
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Yoshida J, Abe S, Takahashi D, Segawa Y, Komai Y, Tsujii H, Matsumoto K, Suzuki H, Onuki Y. Novel quantum criticality in CeRu2Si2 near absolute zero observed by thermal expansion and magnetostriction. PHYSICAL REVIEW LETTERS 2008; 101:256402. [PMID: 19113729 DOI: 10.1103/physrevlett.101.256402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Indexed: 05/27/2023]
Abstract
We report linear thermal expansion and magnetostriction measurements for CeRu2Si2 in magnetic fields up to 52.6 mT and at temperatures down to 1 mK. At high temperatures, this compound showed Landau-Fermi-liquid behavior: The linear thermal expansion coefficient and the magnetostriction coefficient were proportional to the temperature and magnetic field, respectively. In contrast, a pronounced non-Fermi-liquid effect was found below 50 mK. The negative contribution of thermal expansion and magnetostriction suggests the existence of an additional quantum critical point.
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Affiliation(s)
- J Yoshida
- Department of Physics, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
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Donath JG, Steglich F, Bauer ED, Sarrao JL, Gegenwart P. Dimensional crossover of quantum critical behavior in CeCoIn5. PHYSICAL REVIEW LETTERS 2008; 100:136401. [PMID: 18517974 DOI: 10.1103/physrevlett.100.136401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Indexed: 05/26/2023]
Abstract
The nature of quantum criticality in CeCoIn5 is studied by low-temperature thermal expansion alpha(T). At the field-induced quantum critical point at H = 5 T a crossover scale T* approximately 0.3 K is observed, separating alpha(T)/T proportional, variant T(-1) from a weaker T(-1/2) divergence. We ascribe this change to a crossover in the dimensionality of the critical fluctuations which may be coupled to a change from unconventional to conventional quantum criticality. Disorder, whose effect on quantum criticality is studied in CeCoIn(5-x)Sn(x) (0 < or = x < or = 0.18), shifts T* towards higher temperatures.
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Affiliation(s)
- J G Donath
- Max-Planck-Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
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