Strong uniaxial pressure dependencies evidencing spin-lattice coupling and spin fluctuations in Cr2Ge2Te6
Single crystals of Cr2Ge2Te6 were studied by high-resolution capacitance dilatometry to obtain in-plane (B∥ab) and out-of-plane (B∥c) thermal expansion and magnetostriction at temperatures between 2 and 300 K and in magnetic fields up to 15 T. The anomalies in both response functions lead to the “ma...
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| Main Authors: | , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
10 May 2023
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| In: |
Physical review
Year: 2023, Volume: 107, Issue: 18, Pages: 1-8 |
| ISSN: | 2469-9969 |
| DOI: | 10.1103/PhysRevB.107.184421 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1103/PhysRevB.107.184421 Verlag, lizenzpflichtig, Volltext: https://link.aps.org/doi/10.1103/PhysRevB.107.184421 
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| Author Notes: | S. Spachmann, S. Selter, B. Büchner, S. Aswartham, and R. Klingeler |
| Summary: | Single crystals of Cr2Ge2Te6 were studied by high-resolution capacitance dilatometry to obtain in-plane (B∥ab) and out-of-plane (B∥c) thermal expansion and magnetostriction at temperatures between 2 and 300 K and in magnetic fields up to 15 T. The anomalies in both response functions lead to the “magnetoelastic” phase diagrams and separate the paramagnetic (PM), ferromagnetic low-temperature/low-field (LTF) and aligned ferromagnetic (FM) phases. Different signs of magnetostriction anomalies as well as the evolution of thermal expansion anomalies at small fields B∥ab of different magnetic-field dependence clearly supports the scenario of an intermediate region separating PM and LTF phases in finite external in-plane magnetic fields and implies a triple point in the magnetic phase diagram. Simulations of the magnetostriction using the Stoner-Wohlfarth model for uniaxial anisotropy demonstrate that the observed quadratic-in-field behavior in the LTF phase is in line with a rotation of the spins from the preferred c direction into the ab plane. Both the LTF and the PM phase close to TC exhibit very strong pressure dependencies of the magnetization, ∂lnMab/∂pab, of several hundred %/GPa and the transition from the LTF to the FM phase strongly depends on pab (∼−280%/GPa), indicating a strong decrease in the uniaxial anisotropy under applied in-plane pressure. Our data clearly demonstrate the relevance of critical fluctuations and magnetoelastic coupling in Cr2Ge2Te6. |
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| Item Description: | Im Text sind "2" und "6" tiefgestellt Gesehen am 10.07.2023 |
| Physical Description: | Online Resource |
| ISSN: | 2469-9969 |
| DOI: | 10.1103/PhysRevB.107.184421 |