Magnetic ground state of semiconducting transition-metal trichalcogenide monolayers
Magnetic ground state of semiconducting transition-metal trichalcogenide monolayers
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DOI：
10.1103/physrevb.91.235425
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发表时间：
2015-06-16
影响因子：
3.7
通讯作者：
Xiao, Di
中科院分区：
文献类型：
--
作者：
Sivadas, Nikhil;Daniels, Matthew W.;Xiao, Di
具有化学式ABX（3）的层状过渡金属三硫属化物作为二维磁体的潜在候选者最近引起了人们的兴趣。使用密度泛函理论的第一性原理计算，我们调查的Mn和Cr为基础的半导体trichalcogenides单层的磁基态。我们发现，磁性离子之间的第二和第三近邻交换相互作用（J（2）和J（3）），这在以前的理论研究中在很大程度上被忽视，是至关重要的，在确定磁基态。具体地说，我们发现，单层CrSiTe3是一个反铁磁体的锯齿形自旋织构由于显着的贡献从J3，而CrGeTe3是一个铁磁体的居里温度为106 K。Mn化合物（MnPS_3和MnPSe_3）的单分子膜总是表现出反铁磁的Neel序。我们确定了各种交换相互作用的物理起源，并证明了应变可以是一个有效的旋钮，用于调整磁性。可能的磁有序的散装进行了讨论。我们的研究表明，ABX（3）可以成为一个有前途的平台，探索二维磁现象。
Layered transition-metal trichalcogenides with the chemical formula ABX(3) have attracted recent interest as potential candidates for two-dimensional magnets. Using first-principles calculations within density functional theory, we investigate the magnetic ground states of monolayers of Mn- and Cr-based semiconducting trichalcogenides. We show that the second and third nearest-neighbor exchange interactions (J(2) and J(3)) between magnetic ions, which have been largely overlooked in previous theoretical studies, are crucial in determining the magnetic ground state. Specifically, we find that monolayer CrSiTe3 is an antiferromagnet with a zigzag spin texture due to significant contribution from J3, whereas CrGeTe3 is a ferromagnet with a Curie temperature of 106 K. Monolayers of Mn compounds (MnPS3 and MnPSe3) always show antiferromagnetic Neel order. We identify the physical origin of various exchange interactions, and demonstrate that strain can be an effective knob for tuning the magnetic properties. Possible magnetic ordering in the bulk is also discussed. Our study suggests that ABX(3) can be a promising platform to explore two-dimensional magnetic phenomena.