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Teknowijoyo S, Cho K, Timmons EI, Tanatar MA, Krizan JW, Cava RJ, Prozorov R. Low-temperature high-frequency dynamic magnetic susceptibility of classical spin-ice Dy 2Ti 2O 7. J Phys Condens Matter 2021; 33:455802. [PMID: 34380114 DOI: 10.1088/1361-648x/ac1cb0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
Radio-frequency (14.6 MHz) AC magnetic susceptibility,χAC', of Dy2Ti2O7was measured using self-oscillating tunnel-diode resonator. Measurements were made with the excitation AC field parallel to the superimposed DC magnetic field up to 5 T in a wide temperature range from 50 mK to 100 K. At 14.6 MHz, a known broad peak ofχAC'(T)from kHz-range audio-frequency measurements around 15 K for both [111] and [110] directions shifts to 45 K, continuing the Arrhenius activated behavior with the same activation energy barrier ofEa≈ 230 K. Magnetic field dependence ofχAC'along [111] reproduces previously reported low-temperature two-in-two-out to three-in-one-out spin configuration transition at about 1 T, and an intermediate phase between 1 and 1.5 T. The boundaries of the intermediate phase show reasonable overlap with the literature data and connect at a critical endpoint of the first order transition line, suggesting that these features are frequency independent. An unusual upturn of the magnetic susceptibility atT→ 0 was observed in magnetic fields between 1.5 T and 2 T for both magnetic field directions, before fully polarized configuration sets in above 2 T.
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Affiliation(s)
- S Teknowijoyo
- Ames Laboratory, Ames, IA 50011, United States of America
- Department of Physics & Astronomy, Iowa State University, Ames, IA 50011, United States of America
| | - K Cho
- Ames Laboratory, Ames, IA 50011, United States of America
| | - E I Timmons
- Ames Laboratory, Ames, IA 50011, United States of America
- Department of Physics & Astronomy, Iowa State University, Ames, IA 50011, United States of America
| | - M A Tanatar
- Ames Laboratory, Ames, IA 50011, United States of America
- Department of Physics & Astronomy, Iowa State University, Ames, IA 50011, United States of America
| | - J W Krizan
- Department of Chemistry, Princeton University, Princeton, NJ 08544, United States of America
| | - R J Cava
- Department of Chemistry, Princeton University, Princeton, NJ 08544, United States of America
| | - R Prozorov
- Ames Laboratory, Ames, IA 50011, United States of America
- Department of Physics & Astronomy, Iowa State University, Ames, IA 50011, United States of America
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Timmons EI, Tanatar MA, Liu Y, Cho K, Lograsso TA, Kończykowski M, Prozorov R. Mechanical detwinning device for anisotropic resistivity measurements in samples requiring dismounting for particle irradiation. Rev Sci Instrum 2020; 91:073904. [PMID: 32752837 DOI: 10.1063/5.0012053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 06/19/2020] [Indexed: 06/11/2023]
Abstract
Uniaxial stress is used to detwin the samples of orthorhombic iron based superconductors to study their intrinsic electronic anisotropy. Here, we describe the development of a new detwinning setup enabling variable-load stress-detwinning with easy sample mounting/dismounting without the need to re-solder the contacts. It enables the systematic study of the anisotropy evolution as a function of an external parameter when the sample is modified between the measurements. In our case, the external parameter is the dose of 2.5 MeV electron irradiation at low temperature. We illustrate the approach by studying resistivity anisotropy in single crystals of Ba1-xKxFe2As2 at x = 0.25, where the much discussed unusual re-entrance of the tetragonal C4 phase, C4 → C2 → C4, is observed on cooling. With the described technique, we found a significant anisotropy increase in the C2 phase after electron irradiation with a dose of 2.35 C/cm2.
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Affiliation(s)
- E I Timmons
- Ames Laboratory, USDOE, Ames, Iowa 50011, USA
| | - M A Tanatar
- Ames Laboratory, USDOE, Ames, Iowa 50011, USA
| | - Yong Liu
- Ames Laboratory, USDOE, Ames, Iowa 50011, USA
| | - Kyuil Cho
- Ames Laboratory, USDOE, Ames, Iowa 50011, USA
| | | | - M Kończykowski
- Laboratoire des Solides Irradiés, CEA/DRF/lRAMIS, Ecole Polytechnique, CNRS, Institut Polytechnique de Paris, F-91128 Palaiseau, France
| | - R Prozorov
- Ames Laboratory, USDOE, Ames, Iowa 50011, USA
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Kissikov T, Sarkar R, Lawson M, Bush BT, Timmons EI, Tanatar MA, Prozorov R, Bud'ko SL, Canfield PC, Fernandes RM, Curro NJ. Uniaxial strain control of spin-polarization in multicomponent nematic order of BaFe 2As 2. Nat Commun 2018. [PMID: 29535323 PMCID: PMC5849640 DOI: 10.1038/s41467-018-03377-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The iron-based high temperature superconductors exhibit a rich phase diagram reflecting a complex interplay between spin, lattice, and orbital degrees of freedom. The nematic state observed in these compounds epitomizes this complexity, by entangling a real-space anisotropy in the spin fluctuation spectrum with ferro-orbital order and an orthorhombic lattice distortion. A subtle and less-explored facet of the interplay between these degrees of freedom arises from the sizable spin-orbit coupling present in these systems, which translates anisotropies in real space into anisotropies in spin space. We present nuclear magnetic resonance studies, which reveal that the magnetic fluctuation spectrum in the paramagnetic phase of BaFe2As2 acquires an anisotropic response in spin-space upon application of a tetragonal symmetry-breaking strain field. Our results unveil an internal spin structure of the nematic order parameter, indicating that electronic nematic materials may offer a route to magneto-mechanical control. A fundamental understanding of nematic order is one of the most important issues to explore in the high temperature superconductors. Here, the authors unveil an internal spin structure of the nematic order in BaFe2As2 by using nuclear magnetic resonance under precisely controlled tunable strain.
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Affiliation(s)
- T Kissikov
- Department of Physics, University of California, Davis, CA, 95616, USA
| | - R Sarkar
- Institute for Solid State Physics, TU Dresden, D-01069, Dresden, Germany
| | - M Lawson
- Department of Physics, University of California, Davis, CA, 95616, USA
| | - B T Bush
- Department of Physics, University of California, Davis, CA, 95616, USA
| | - E I Timmons
- Ames Laboratory U.S. DOE and Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA
| | - M A Tanatar
- Ames Laboratory U.S. DOE and Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA
| | - R Prozorov
- Ames Laboratory U.S. DOE and Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA
| | - S L Bud'ko
- Ames Laboratory U.S. DOE and Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA
| | - P C Canfield
- Ames Laboratory U.S. DOE and Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA
| | - R M Fernandes
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - N J Curro
- Department of Physics, University of California, Davis, CA, 95616, USA.
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Tanatar MA, Bondarenko VA, Timmons EI, Prozorov R. Modular portable unit for thermal conductivity measurements in multiple cryogenic/magnetic field environments. Rev Sci Instrum 2018; 89:013903. [PMID: 29390721 DOI: 10.1063/1.5001708] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A modular design for a miniature thermal conductivity cell suitable for a dilution refrigerator and other sample-in-vacuum cryogenic environments with different magnet options is described. The sample is mounted once and the contacts remain in place when the unit is repositioned or transported between different magnets and cryostats. This mobility enables comprehensive measurements with access to specific options, such as vector magnet in one lab and ultra-high field in another. This design enables significant expansion of the temperature range by using not only dilution refrigerators but also 3He, 4He cryostats and even ubiquitous Quantum Design Physical Property Measurement System.
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Affiliation(s)
- M A Tanatar
- Ames Laboratory US DOE, Ames, Iowa 50011, USA
| | | | - E I Timmons
- Ames Laboratory US DOE, Ames, Iowa 50011, USA
| | - R Prozorov
- Ames Laboratory US DOE, Ames, Iowa 50011, USA
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Tanatar MA, Böhmer AE, Timmons EI, Schütt M, Drachuck G, Taufour V, Kothapalli K, Kreyssig A, Bud'ko SL, Canfield PC, Fernandes RM, Prozorov R. Origin of the Resistivity Anisotropy in the Nematic Phase of FeSe. Phys Rev Lett 2016; 117:127001. [PMID: 27689292 DOI: 10.1103/physrevlett.117.127001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Indexed: 06/06/2023]
Abstract
The in-plane resistivity anisotropy is studied in strain-detwinned single crystals of FeSe. In contrast to other iron-based superconductors, FeSe does not develop long-range magnetic order below the tetragonal-to-orthorhombic transition at T_{s}≈90 K. This allows for the disentanglement of the contributions to the resistivity anisotropy due to nematic and magnetic orders. Comparing direct transport and elastoresistivity measurements, we extract the intrinsic resistivity anisotropy of strain-free samples. The anisotropy peaks slightly below T_{s} and decreases to nearly zero on cooling down to the superconducting transition. This behavior is consistent with a scenario in which the in-plane resistivity anisotropy is dominated by inelastic scattering by anisotropic spin fluctuations.
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Affiliation(s)
- M A Tanatar
- Ames Laboratory, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | | | - E I Timmons
- Ames Laboratory, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - M Schütt
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - G Drachuck
- Ames Laboratory, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - V Taufour
- Ames Laboratory, Ames, Iowa 50011, USA
| | - K Kothapalli
- Ames Laboratory, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - A Kreyssig
- Ames Laboratory, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - S L Bud'ko
- Ames Laboratory, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - P C Canfield
- Ames Laboratory, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - R M Fernandes
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - R Prozorov
- Ames Laboratory, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
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