论文标题
van der waals feps3中的固有磁和光学特性的晶体各向异性影响
Crystal anisotropy implications on the intrinsic magnetic and optical properties in van der Waals FePS3
论文作者
论文摘要
抗铁磁(AFM)FEPS3最近对其在自旋相关设备中的潜在应用引起了重大兴趣。单层由蜂窝网络组成,该网络由远程自旋交互的稳定,并具有Fe-Atoms的锯齿形或Neel排列。这项研究首次暴露了侧晶体失真对FEPS3的磁布置和光学特性的强烈影响。通过将光致发光(PL)的观测与单晶XRD相关联,该影响是解密的,该观测发现在A/B晶体学平面中发现各向异性。因此,在FEPS3中诱导反转对称性的破裂,从而导致其电子和光学转变变化。 MPL观测结果表现出意外的带边缘圆形的重组发射,而偏斜的过渡是线性极化的。同样,温度依赖的MPL测量反映在低温下的曲折-AFM以及在中温度下的锯齿形或Neel的共存。 Fe Atom最近邻居之间自旋交换相互作用中各向异性实现各向异性的理论计算显示,稳定的锯齿形排列偏离了A轴。此外,电子带边缘的DFT计算在退化的对称点(K+/K-)中预测锯齿形结构的分裂状态,而对于Neel排列,则预测了非分类结构。强调包含晶体学各向异性参数的重要性,以模拟实验观测。
Antiferromagnetic (AFM) FePS3 has gained significant interest recently for its potential applications in spin-related devices. A single layer is comprised of a honeycomb network, stabilized by long-range spin-exchange interactions, with a zigzag or Neel arrangement of the Fe-atoms. This study exposed, for the first time, a strong impact of lateral crystal distortion on the magnetic arrangement and optical properties of FePS3. This impact was deciphered by correlating photoluminescence (PL) observations with single-crystal XRD which uncovered anisotropy in the a/b crystallographic plane. Thus, induceing a breakage in the inversion symmetry in FePS3 causing changes in it's electronic and optical transitions. The MPL observations exhibited an unexpected band-edge circularly polarized recombination emission, while off-band-edge transitions were linearly polarized. Also, temperature-dependent MPL measurements reflected zigzag-AFM at low temperatures and the coexistence of zigzag or Neel at mid temperatures. Theoretical calculation implementing anisotropy in spin-exchange interactions among Fe atom's nearest neighbors revealed stabilized zigzag arrangement tilted away from the a-axis. Furthermore, DFT calculations of the electronic band-edge predicted split states in degenerate symmetric points (K+/K-) for zigzag structure and non-degenerate for the Neel arrangement. Highlighting the importance of the inclusion of a crystallographic anisotropy parameter for the simulation of the experimental observations.