论文标题
ga $ _ {1-x} $ v $ _x $ sb化合物的结构和磁性理论研究
Theoretical study of structure and magnetism of Ga$_{1-x}$V$_x$Sb compounds for spintronic applications
论文作者
论文摘要
在本文中，通过第一原则计算，系统地研究了锌 - 搅拌GA1-XVXSB化合物的结构，电子和磁性，从稀释掺杂情况到极端掺杂限制。 V原子更喜欢替代GA原子，而在富含GA的生长条件下，SB富含SB的地层能量低。同时，SBGA抗铁矿缺陷可以有效地降低替代过程的能量障碍，从0.85 eV降低到0.53 eV。 V原子在GASB晶格中的扩散是通过元稳定的间隙位点，能屏障为0.6 eV。在低V浓度X = 0.0625处，V原子更喜欢均匀分布和它们之间的抗铁磁耦合。但是，由于X = 0.5的X = 0.5，V原子之间的磁耦合变化为铁磁，这是由于相邻V原子的EG和T2G状态之间的superexchange相互作用增强。在X = 1.00的极限限制下，我们发现锌 - 蓝色VSB及其类似物VAS和VP是固有的Ferromagneitc半导体，在Curie温度下，光吸收的变化很大。这些结果表明，GA1-XVXSB化合物可以提供设计新的电子，自旋和光电设备的平台。
In this paper, the structural, electronic and magnetic properties of Zinc-blende Ga1-xVxSb compounds, with x from dilute doping situation to extreme doping limiting, were systematically investigated by first-principles calculations. V atoms prefer to substitute the Ga atoms and the formation energy is lower in Sb-rich than Ga-rich growth condition. Meantime, the SbGa antisite defects can effectively decrease the energy barrier of substitution process, from 0.85 eV to 0.53 eV. The diffusion of V atom in GaSb lattice is through meta-stable interstitial sites with an energy barrier of 0.6 eV. At a low V concentration x = 0.0625, V atoms prefer a homogeneous distribution and an antiferromagnetic coupling among them. However, starting from x = 0.5, the magnetic coupling among V atoms changes to be ferromagnetic, due to enhanced superexchange interaction between eg and t2g states of neighbouring V atoms. At the extreme limiting of x = 1.00, we found that Zinc-blende VSb as well as its analogs VAs and VP are intrinsic ferromagneitc semiconductors, with a large change of light absorption at the curie temperature. These results indicate that Ga1-xVxSb compounds can provide a platform to design the new electronic, spintronic and optoelectronic devices.
