摘要：
Magnetic semiconductors, with semiconductivity and ferromagnetism simultaneously, have promising important applications as storage devices. However, the ordered ferromagnetic state easily suffers from enhanced thermal fluctuation, inducing a very small Curie temperature. Here we have successfully predicted a new 2D small-gap MoS(2)magnetic semiconductor. Instead, almost all of the reported MoS(2)phase was nonmagnetic whether it exhibited semiconducting or metal behavior. Monte Carlo simulations showed that its Curie temperature could approach 130 K and could be further enhanced through applying biaxial tensile strain. The revealed atomic bonding pattern paves a new way to explore novel electronic and magnetic materials.
摘要：
The high-spin-polarized electronic state has been a central concept in applications such as storage materials and magnetic injection sources. In this work, we predicted the existence of a novel 2D CrO(2)lattice, wherein electrons around the Fermi level were indicated to be completely spin-polarized with an ultra-wide energy range. Monte Carlo simulations showed that such an ordered spin state could be maintained to a temperature of 280 K, and further enhanced through strain or hole doping. The predicted structure here inspired us to archive ideal 2D materials as magnetic storage devices or spin injection sources.
摘要：
Low-dimensional nanostructures are expected to play an important role in spintronics. However, in low-dimensional systems, thermal fluctuations become more significant, which makes long-range magnetic ordering thermodynamically unfavorable. For example, as predicted by the Ising model, 1D magnetic order cannot survive, even at an arbitrary low finite temperature. In this study, utilizing a nanoproximity effect, we design a MoS2 nanoribbon material to stabilize 1D magnetic order without requiring the explicit application of an external magnetic field. The designed MoS2 nanoribbon has a new edge-reconstruction pattern, which is much more stable than previously reported structures. As a novel electronic property, one edge is nonmagnetic but conductive, and the opposite edge contains a magnetic moment in the predicted reconstruction pattern. Therefore, a bias voltage can drive a current along the former edge, which then generates a magnetic field at the opposite edge to stabilize the 1D magnetic order there. This result opens a new avenue to realize the integrated electrical control of magnetism.
作者机构：
[Xiaohui Deng; Mingsu Si; Jiayu Dai] Department of Physics and Electronic Information Science,Hengyang Normal University;[Xiaohui Deng; Mingsu Si; Jiayu Dai] Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education,Lanzhou University;[Xiaohui Deng; Mingsu Si; Jiayu Dai] Department of Physics,College of Science,National University of Defense Technology
会议名称：
第九届计算纳米科学与新能源材料国际研讨会
会议时间：
2016-06-22
会议地点：
中国上海
摘要：
<正>Modern electronic technology based on silicon semiconductor is faced with the limit from thermal effect and quantum effect.Therefore,to look for new alternative materials becomes to be an important
作者机构：
[Zeng, Jing; Deng, Xiaohui] Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421008, Peoples R China.;[Si, Mingsu] Lanzhou Univ, Minist Educ, Key Lab Magnetism & Magnet Mat, Lanzhou 730000, Peoples R China.;[Lu, Wei] Hong Kong Polytech Univ, Univ Res Facil Mat Characterizat & Device Fabrica, Hong Kong, Hong Kong, Peoples R China.
通讯机构：
[Deng, Xiaohui] H;Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421008, Peoples R China.
关键词：
EPL;Europhysics Letters
摘要：
The modulation of the band gap in the two-dimensional carbon materials is of importance for their applications as electronic devices. By first-principles calculations, we propose a model to control the band gap size of <i>γ<i/>-graphyne. The model is named as <i>p<i/>-<i>n<i/> codoping, <i>i.e.<i/>, using B and N atoms to codope into <i>γ<i/>-graphyne. After codoping, the B atom plays the role of <i>p<i/> dopant and the N atom acts as <i>n<i/> dopant. The Fermi energy level returns around the forbidden zone and the band gap of <i>γ<i/>-graphyne becomes bigger or smaller. Moreover, the gaps exhibit an oscillating behaviour in the different codoping configurations. The proposed model serves as new insights for a better modulation of the electronic properties of 2D carbon materials.
作者机构：
[Zeng, Jing; Deng, Xiaohui] Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421008, Peoples R China.;[Si, Mingsu] Lanzhou Univ, Minist Educ, Key Lab Magnetism & Magnet Mat, Lanzhou 730000, Peoples R China.;[Lu, Wei] Hong Kong Polytech Univ, Univ Res Facil Mat Characterizat & Device Fabrica, Hong Kong, Hong Kong, Peoples R China.
通讯机构：
[Deng, Xiaohui] H;Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421008, Peoples R China.
摘要：
A theoretical model is presented that reveals the mechanism of spontaneous boron doping of graphene and is consistent with the microwave plasma experiment choosing trimethylboron as the doping source (Tang et al. (2012) [19]). The spontaneous boron doping originates from the synergistic effect of B and other groups (C, H, CH, CH2 or CH3) decomposing from trimethylboron. This work successfully explains the above experimental phenomenon and proposes a novel and feasible method aiming at B doping of graphene. The mechanism presented here may be also suitable for other two-dimensional carbon-based materials. (C) 2016 Elsevier B.V. All rights reserved.
摘要：
A photoswitched single-molecule junction, a stable and reversible single-molecule electrical switch, has been successfully prepared by means of molecular engineering (2016 Science 352 1443). In this work we use a first-principles computational approach to investigate the spin valve effect of an azobenzene-based spin optoelectronic device. Our results demonstrate that the magnetoresistive ratio of the spin optoelectronic device is only about 65% when the azobenzene is in cis configuration, which is a low performance for practical applications. However, the magnetoresistive ratio of the device can be enhanced to about 2775% when the cis configuration of the azobenzene is changed into the trans configuration by applying a pulse of light. As a consequence, photoexcitation provides an effective way to obtain a high-performance spin optoelectronic device.
