论文标题
Lacunar Spinel Gamo $ _4 $ SE $ _8 $
Structural evolution and skyrmionic phase diagram of the lacunar spinel GaMo$_4$Se$_8$
论文作者
论文摘要
在$ ab_4q_8 $ lacunar尖晶石中，根据四面体$ b_4 $簇的群间和群内相互作用来描述电子结构，并且调整这些可以导致无数引人入胜的电子和磁接地状态。在这项工作中，我们采用磁性测量，同步X射线和中子散射，以及第一原理电子结构计算，以检查Gamo $ _4 $ SE $ _8 $中的结构和磁相演变之间的耦合，包括在磁性相图中出现Skyrmionic Segime。我们表明，室温立方$ f \ overline {4} 3M $结构之间的两个不同的Jahn Teller扭曲之间的竞争导致基态的共存$ 3M $ $ 3M $ apeas和Arcastable $ IMM2 $相位。这两个阶段的磁性特性在计算上显示出非常不同的磁性，其中$ IMM2 $相位表现出单轴铁磁剂，$ 3M $ $相位托管一个复杂的磁性相图，包括平衡Néel-type天空稳定，从几乎$ t $ = 28 k = 28 k下降到$ t $ t $ t $ = 2 k = 2 k = 2 k = 2 k，最低的测量温度，最低的温度。小型结构失真引起的磁性行为的巨大变化表明，gamo $ _4 $ se $ _8 $是一种令人兴奋的候选材料，用于通过$机械手段来调整非常规磁性的$。
In the $AB_4Q_8$ lacunar spinels, the electronic structure is described on the basis of inter- and intra-cluster interactions of tetrahedral $B_4$ clusters, and tuning these can lead to myriad fascinating electronic and magnetic ground states. In this work, we employ magnetic measurements, synchrotron X-ray and neutron scattering, and first-principles electronic structure calculations to examine the coupling between structural and magnetic phase evolution in GaMo$_4$Se$_8$, including the emergence of a skyrmionic regime in the magnetic phase diagram. We show that the competition between two distinct Jahn-Teller distortions of the room temperature cubic $F\overline{4}3m$ structure leads to the coexistence of the ground state $R3m$ phase and a metastable $Imm2$ phase. The magnetic properties of these two phases are computationally shown to be very different, with the $Imm2$ phase exhibiting uniaxial ferromagnetism and the $R3m$ phase hosting a complex magnetic phase diagram including equilibrium Néel--type skyrmions stable from nearly $T$ = 28 K down to $T$ = 2 K, the lowest measured temperature. The large change in magnetic behavior induced by a small structural distortion reveals that GaMo$_4$Se$_8$ is an exciting candidate material for tuning unconventional magnetic properties $via$ mechanical means.
