Pressure control of the magnetic anisotropy of the quasi-two-dimensional van der Waals ferromagnet Cr2Ge2Te6
Pressure control of the magnetic anisotropy of the quasi-two-dimensional van der Waals ferromagnet Cr2Ge2Te6
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DOI：
10.1103/physrevb.103.024404
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发表时间：
2021-01
影响因子：
3.7
通讯作者：
T. Sakurai;B. Rubrecht;L. Corredor;R. Takehara;M. Yasutani;J. Zeisner;A. Alfonsov;S. Selter;S. Aswartham;A. Wolter;B. Büchner;H. Ohta;V. Kataev
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文献类型：
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作者：
T. Sakurai;B. Rubrecht;L. Corredor;R. Takehara;M. Yasutani;J. Zeisner;A. Alfonsov;S. Selter;S. Aswartham;A. Wolter;B. Büchner;H. Ohta;V. Kataev
我们报告了${\mathrm{Cr}}_{2}{\mathrm{Ge}}_{2}{\mathrm{Te}}_{6}$的静态磁化和铁磁共振（FMR）的压力相关测量结果，以解决这种准二维范德华磁体的铁磁相的性质。在3.4 GPa静水压力下的静磁数据显示，铁磁性逐渐受到抑制，其表现为临界转变温度降低，转变宽度变宽，完全饱和磁化所需的磁场增大${M}_{\mathrm{s}}$。当压力达到2.8 GPa时，${M}_{\mathrm{s}}\ensuremath{\simeq}3{\ensuremath{\mu}}_{\mathrm{B}}/\mathrm{Cr}$的值在误差条内保持恒定。静水压力为2.39 GPa时，FMR信号的各向异性不断减小，表明易轴型磁晶各向异性能（MAE）降低。FMR数据的定量分析表明，在此压力下，MAE常数${K}_{\mathrm{U}}$虽然变得越来越小，但仍然是有限的和正的，即易轴型。因此，最近讨论的在${\mathrm{Cr}}_{2}{\mathrm{Ge}}_{2}{\mathrm{Te}}_{6}$中切换磁晶各向异性符号的可能性，如果可能的话，只能在更高的压力下进行，因为在压力下观察到铁磁性的减弱。这种情况可能与设计含有${\mathrm{Cr}}_{2}{\mathrm{Ge}}_{2}{\mathrm{Te}}_{6}$层的应变工程功能异质结构有关。
We report the results of the pressure-dependent measurements of the static magnetization and of the ferromagnetic resonance (FMR) of ${\mathrm{Cr}}_{2}{\mathrm{Ge}}_{2}{\mathrm{Te}}_{6}$ to address the properties of the ferromagnetic phase of this quasi-two-dimensional van der Waals magnet. The static magnetic data at hydrostatic pressures up to 3.4 GPa reveal a gradual suppression of ferromagnetism in terms of a reduction of the critical transition temperature, a broadening of the transition width, and an increase of the field necessary to fully saturate the magnetization ${M}_{\mathrm{s}}$. The value of ${M}_{\mathrm{s}}\ensuremath{\simeq}3{\ensuremath{\mu}}_{\mathrm{B}}/\mathrm{Cr}$ remains constant within the error bars up to a pressure of 2.8 GPa. The anisotropy of the FMR signal continuously diminishes in the studied hydrostatic pressure range up to 2.39 GPa, suggesting a reduction of the easy-axis-type magnetocrystalline anisotropy energy (MAE). A quantitative analysis of the FMR data gives evidence that up to this pressure the MAE constant ${K}_{\mathrm{U}}$, although getting significantly smaller, still remains finite and positive, i.e., of the easy-axis type. Therefore, a recently discussed possibility of switching the sign of the magnetocrystalline anisotropy in ${\mathrm{Cr}}_{2}{\mathrm{Ge}}_{2}{\mathrm{Te}}_{6}$ could only be expected at still higher pressures, if possible at all, due to the observed weakening of the ferromagnetism under pressure. This circumstance may be of relevance for the design of strain-engineered functional heterostructures containing layers of ${\mathrm{Cr}}_{2}{\mathrm{Ge}}_{2}{\mathrm{Te}}_{6}$.