Controlling magnetism of MoS2 sheets by embedding transition-metal atoms and applying strain.
Controlling magnetism of MoS2 sheets by embedding transition-metal atoms and applying strain.
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DOI：
10.1039/c3cp52832d
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发表时间：
2013-10
期刊：
影响因子：
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通讯作者：
Yungang Zhou;Qiulei Su;Zhiguo Wang;H. Deng;X. Zu
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文献类型：
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作者：
Yungang Zhou;Qiulei Su;Zhiguo Wang;H. Deng;X. Zu
由于最近在生长或饱和现有空位期间过渡金属(TM)原子被取代在MoS2纳米结构中的实验成就(Sun等人，ACS Nano，2013，7,3506；Deepak等人，J.Am化学。Soc.，2007,129,12549)，我们用密度泛函理论研究了MoS_2薄层中一系列3d Tm原子的磁性，发现Mn，Fe，Co，Ni，Cu和Zn取代能在MoS_2薄层中诱导磁性。Tm原子的局域化未配对的3D电子对磁矩的引入做出了响应。根据Tm原子的种类，取代的MoS_2片可以是金属、半导体或半金属。值得注意的是，施加的弹性应变可以用来控制Tm-3D轨道的自旋分裂强度，从而有效地操纵Tm取代的MoS_2薄片的磁性。研究发现，随着拉伸应变的增加，MnS_2和Fe取代MoS_2的磁矩单调增加，而Co、Ni、Cu和Zn取代的MoS_2的磁矩则随拉应变的增加而先增大后减小。提出了一种定性解释磁性随弹性应变变化的机理。磁弹性效应的发现对于在MoS_2纳米结构上制备应变驱动自旋器件具有重要的技术意义，这使得我们可以超越目前仅限于石墨烯和BN基纳米结构中的自旋器件的范围。
Prompted by recent experimental achievement of transition metal (TM) atoms substituted in MoS2 nanostructures during growth or saturating existing vacancies (Sun et al., ACS Nano, 2013, 7, 3506; Deepak et al., J. Am. Chem. Soc., 2007, 129, 12549), we explored, via density functional theory, the magnetic properties of a series of 3d TM atoms substituted in a MoS2 sheet, and found that Mn, Fe, Co, Ni, Cu and Zn substitutions can induce magnetism in the MoS2 sheet. The localizing unpaired 3d electrons of TM atoms respond to the introduction of a magnetic moment. Depending on the species of TM atoms, the substituted MoS2 sheet can be a metal, semiconductor or half-metal. Remarkably, the applied elastic strain can be used to control the strength of the spin-splitting of TM-3d orbitals, leading to an effective manipulation of the magnetism of the TM-substituted MoS2 sheet. We found that the magnetic moment of the Mn- and Fe-substituted MoS2 sheets can monotonously increase with the increase of tensile strain, while the magnetic moment of Co-, Ni-, Cu- and Zn-substituted MoS2 sheets initially increases and then decreases with the increase of tensile strain. An instructive mechanism was proposed to qualitatively explain the variation of magnetism with elastic strain. The finding of the magnetoelastic effect here is technologically important for the fabrication of strain-driven spin devices on MoS2 nanostructures, which allows us to go beyond the current scope limited to the spin devices within graphene and BN-based nanostructures.