论文标题
高分辨率衍射揭示了四方Cumnas中的磁弹性耦合和相干相分离
High-resolution diffraction reveals magnetoelastic coupling and coherent phase separation in tetragonal CuMnAs
论文作者
论文摘要
四方cumnas是第一个抗fiferromagnet，据报道，néel载体的重新定位是通过反旋转电流效应发生的。形成相四方cumnas的一个复杂因素是形成几乎相同的化学计量法的正骨相。据报道，纯相四方Cumnas需要过量的CU才能在传统的固态合成反应中维持单相。在这里，我们表明衍射模式上的细微差异信号不均匀性和相位分离，即使在Cu-rich Cu $ _ {1.18} $ Mn $ _ {0.82} $ AS中也是如此。从量热法和磁力计测量值中，我们确定了对应于Néel温度（T $ _N $）的两个过渡，并确定了Cu $ _ {1.18} $ Mn $ _ MN $ _ {0.82} $ and Cumn and cumn and Cumn as and Cumn as and Cumn as and Cumn as and cumn as and cumn aS and cumn a and cum _ as $ _ {0.964} $ s $ s $ s $ s $ s $ s $ s $ as and cu $ _ {1.18} $ _ {0.964} $ s $ as as and vermagnet trantition。这些过渡具有清晰的晶体学特征，在原位加热和冷却后的晶格参数中可以直接观察到。在高温下发生的脊柱分解可能会产生不混溶性和相位分离，室温附近的铁磁过渡的存在必须进一步研究其对电交换行为的影响。
Tetragonal CuMnAs was the first antiferromagnet where reorientation of the Néel vector was reported to occur by an inverse spin galvanic effect. A complicating factor in the formation of phase-pure tetragonal CuMnAs is the formation of an orthorhombic phase with nearly the same stoichiometry. Pure-phase tetragonal CuMnAs has been reported to require an excess of Cu to maintain a single phase in traditional solid state synthesis reactions. Here we show that subtle differences in diffraction patterns signal pervasive inhomogeneity and phase separation, even in Cu-rich Cu$_{1.18}$Mn$_{0.82}$As. From calorimetry and magnetometry measurements, we identify two transitions corresponding to the Néel temperature (T$_N$) and an antiferromagnet to weak ferromagnet transition in Cu$_{1.18}$Mn$_{0.82}$As and CuMn$_{0.964}$As$_{1.036}$. These transitions have clear crystallographic signatures, directly observable in the lattice parameters upon in-situ heating and cooling. The immiscibility and phase separation could arise from a spinoidal decomposition that occurs at high temperatures, and the presence of a ferromagnetic transition near room temperature warrants further investigation of its effect on the electrical switching behavior.
