稀磁半导体Cr_xMn_(1-x)Te的第一性原理计算

First Principles Calculation of Diluted Magnetic Semiconductor Cr_xMn_(1-x)Te

根据CrTe和MnTe各种结构的稳定性,选取具有NiAs结构、岩盐结构和闪锌矿结构的CrTe为基本骨架,以Mn原子替换Cr原子形成掺杂的稀磁半导体CrxMn1-xTe.使用基于密度泛函理论的VASP软件包,计算其形成能、态密度和磁矩,并比较不同x值对性能的影响.结果表明,掺杂后3种结构的稳定性为NiAs结构>岩盐结构>闪锌矿结构;Mn原子掺杂NiAs结构后,NiAs结构发生向闪锌矿结构的相变,对闪锌矿结构掺杂未发生相变;3种结构的磁矩均随Mn原子的增多而增大.

According to the stability of CrTe and MnTe structures,we selected the NiAs,RS and ZB structures of CrTe as the basic framework,and used Mn atoms to replace Cr atoms to form the diluted magnetic semiconductor CrxMn1-xTe.We used VASP code based on the density functional theory to calculate the formation energy to find the most stable structure,and to calculate the density of state and magnetic moment of CrxMn1-xTe,and compared the effects of different xvalues on the performance.We found that the stability sequence of the three kinds of structures from high to low is NiAs structure,RS structure and ZB structure.The structure of NiAs doped with Mn atoms caused the phase to transfer to ZB structure.ZB structure doped with Mn atoms did not cause the phase change.Finally,we researched the magnetic properties of the three structures,the magnetic moment increases with the increase of Mn atoms.