Strong uniaxial pressure dependencies evidencing spin-lattice coupling and spin fluctuations in Cr${}_2$Ge${}_2$Te${}_6$

Abstract

Single crystals of Cr${}_2$Ge${}_2$Te${}_6$ were studied by high-resolution capacitance dilatometry to obtain in-plane ($B\parallel ab$) and out-of-plane ($B\parallel c$) 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. The presence of two distinct thermal expansion anomalies at small fields $B\parallel ab$ of different magnetic field dependence clearly supports the scenario of an intermediate region separating PM and LTF phases and is indicative of a tricritical point. 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 T${}_{\mathrm{C}}$ exhibit very strong pressure dependencies of the magnetization, $\partial \ln M_{\mathrm{ab}}/\partial p_{\mathrm{ab}}$, of several hundred %/GPa and also the transition from the LTF to the FM phase strongly depends on $p_{\mathrm{ab}}$ ($\sim -$280%/GPa), indicating a strong decrease of the uniaxial anisotropy under applied in-plane pressure. Our data clearly demonstrate the relevance of critical fluctuations and magnetoelastic coupling in Cr${}_2$Ge${}_2$Te${}_6$.

7 pages, 5 figures

References in corpus (10)

• Possible Kitaev Quantum Spin Liquid State in 2D Materials with S=3/2
• Critical behavior of quasi-two-dimensional semiconducting ferromagnet CrGeTe${}_3$
• Synthesis, Engineering, and Theory of 2D van der Waals Magnets
• Great enhancement of Curie temperature and magnetic anisotropy in two-dimensional van der Waals magnetic semiconductor heterostructures
• Nearly room temperature ferromagnetism in pressure-induced correlated metallic state of van der Waals insulator CrGeTe${}_3$
• Pressure-induced huge increase of Curie temperature of the van der Waals ferromagnet VI3
• Pressure control of the magnetic anisotropy of the quasi-two-dimensional van der Waals ferromagnet Cr${}_2$Ge${}_2$Te${}_6$
• Exotic Magnetic and Electronic Properties of Layered CrI3 Single Crystals Under High Pressure
• Strong effects of uniaxial pressure and short-range correlations in Cr2Ge2Te6
• Uniaxial pressure effects in the two-dimensional van-der-Waals ferromagnet CrI${}_3$

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