Remarkably enhanced ferromagnetism in a super-exchange governed Cr2Ge2Te6 monolayer via molecular adsorption
Remarkably enhanced ferromagnetism in a super-exchange governed Cr2Ge2Te6 monolayer via molecular adsorption
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通过分子吸附显着增强超交换控制的 Cr2Ge2Te6 单层中的铁磁性
DOI：
10.1039/c8tc05530k
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发表时间：
2019-05-07
影响因子：
6.4
通讯作者：
Zhang, Gang
中科院分区：
文献类型：
--
作者：
He, Junjie;Ding, Guangqian;Zhang, Gang
在过去的十年中，利用分子吸附来操纵二维材料的电子性质已经被广泛报道。然而，分子吸附对固有2D磁体的磁性的影响尚未得到充分理解。受原子薄Cr2 Ge 2 Te 6和CrI 3晶体内禀二维铁磁性发现的启发，本文采用密度泛函理论系统研究了气体分子CO、CO2、H2O、N2-、NH3、NO、NO2、O-2和SO2在Cr2 Ge 2 Te 6（CGT）单分子膜底面上的吸附.研究了气体分子吸附Cr_2Ge_2Te_6单层膜的结构、能量、电荷转移、功函数以及电子和磁性。已经发现，气体分子的吸附显着影响的电子和磁性的CGT片。结果表明，分子的吸附可以有效地提高CGT片的铁磁性和居里温度。值得注意的是，通过吸附NO和NO2，分别实现了铁磁性和T-C的38%和32%的显着增强。此外，NO2吸附CGT表现出的电子转移到金属。铁磁性的增强和电子结构的可调可以归因于大量的电荷转移以及前线分子轨道的排列。这项研究的结果不仅揭示了对2D磁体的环境影响的令人兴奋的见解，而且还提供了一种新的候选NO2气体传感器。
Manipulation of the electronic properties of 2D materials with molecular adsorption has been widely reported in the past decade. However, the impact of adsorption of molecules on the magnetism of intrinsic 2D magnets is not yet sufficiently understood. Inspired by the recent discovery of intrinsic 2D ferromagnetism in atomically thin Cr2Ge2Te6 and CrI3 crystals, in this investigation, the adsorption of gas molecules including CO, CO2, H2O, N-2, NH3, NO, NO2, O-2 and SO2 on the basal plane of a Cr2Ge2Te6 (CGT) monolayer was systematically investigated by density functional theory. The structures, energy, charge transfer, work function, and electronic and magnetic properties of the gas molecule adsorbed Cr2Ge2Te6 monolayers were explored. It has been found that the adsorption of gas molecules significantly influences the electronic and magnetic properties of a CGT sheet. It was observed that the adsorption of molecules could effectively enhance the ferromagnetism and Curie temperature (T-C) of the CGT sheet. Notably, a remarkable enhancement of ferromagnetism and T-C by 38% and 32% was achieved by the adsorption of NO and NO2, respectively. Moreover, NO2 adsorbed CGT exhibits a semiconductor-to-metal transition. The enhanced ferromagnetism and tunable electronic structure could be ascribed to the considerable charge transfer as well as to the alignment of the frontier molecular orbital. The outcome of this study reveals not only exciting insights into the environmental effect on 2D magnets but also provides a new candidate as a NO2 gas sensor.