Concurrent Pressure-Induced Spin-State Transitions and Jahn–Teller Distortions in MnTe
Concurrent Pressure-Induced Spin-State Transitions and Jahn–Teller Distortions in MnTe
复制标题
MnTe 中并发压力诱导的自旋态跃迁和 Jahn-Teller 畸变
DOI：
10.1021/acs.chemmater.1c04199
复制
发表时间：
2022
影响因子：
8.6
通讯作者：
Yusheng Zhao
中科院分区：
文献类型：
--
作者：
Pei Wang;Sheng-Cai Zhu;Yongtao Zou;Haiyan Chen;Ying Liu;Weiwei Li;Jian Chen;Jinlong Zhu;Liusuo Wu;Shanmin Wang;Wenge Yang;Yuming Xiao;Paul Chow;Liping Wang;Yusheng Zhao
伴随电磁晶格耦合的合作Jahn-Teller（JT）畸变在材料科学中的许多重要现象中起着至关重要的作用。在八面体配合物中，高自旋3d 4和3d 9组态的JT畸变是常见的，但类似地，由于提升t2 gorbitals的简并度而导致的大畸变迄今为止很少被观察到。本文报道了在MnTe中发现的压致合作JT效应，并伴随有高达12.8%的体积崩塌和磁矩崩塌，在20.9GPa下，磁矩从S = 5/2崩塌到S = 1/2.第一性原理计算表明，p-d杂化减弱和d态局域化增强导致Mn ~（2+）（d5）的t_2轨道简并度提升，从而诱导了协同JT效应触发的电磁晶格耦合.这些发现提出了一种新的机制，合作JT变形通过压力诱导的配体变形在反铁磁材料。
Cooperative Jahn–Teller (JT) distortion accompanied by electromagnetic lattice coupling plays a crucial role in numerous important phenomena in materials science. The JT distortion occurring in high-spin 3d4and 3d9configurations in octahedral complexes is common, but similarly, large distortion due to lifting the degeneracy of t2gorbitals has so far seldomly been observed. Here, we report the discovery of the pressure-induced cooperative JT effect coupled with a large volume collapse of ∼12.8% and a magnetic moment collapse fromS= 5/2 toS= 1/2 at ∼20.9 GPa in MnTe. The first-principles calculation indicates that weakened p–d hybridization and enhanced d state localization result in lifting t2gorbital degeneracy in Mn2+(d5), which induced a cooperative JT effect-triggered electromagnetic lattice coupling. These findings suggest a new mechanism for the cooperative JT distortion via pressure-induced ligand distortion in antiferromagnetic materials.