Zn1-xMnxS（001）稀磁半导体薄膜的能量稳定性、磁性和电子结构

Energy Stabilities, Magnetic Properties, and Electronic Structures of Diluted Magnetic Semiconductor Zn1-xMnxS（001） Thin Films

通过基于广义梯度近似的总能密度泛函理论研究不同Mn掺杂浓度的ZnS（001）薄膜的电学和磁学特性．计算单个Mn原子和两个Mn原子处于各种掺杂位置及不同的磁耦合状态时的能量稳定性．计算了单个Mn原子掺杂和两个Mn原子掺杂的ZnS（001）薄膜的态密度．不同掺杂组态的p-d杂化的程度不同.不同掺杂组态，Mn原子所处的晶场环境不同，所以不同掺杂组态的Mn的3d分波态密度峰的劈裂有很大的不同．掺杂两个Mn原子时，得到三种稳定组态的基态都是反铁磁态，分析了以上三种能量稳定的组态中，两个Mn原了在不同磁耦合状态下的3d态密度图．当两原予为铁磁耦合时，由于d—d电子相互作用，使反键态的态密度峰明显加宽．随着Mn掺杂浓度的增加，Mn原子有相互靠近，并围绕S原子形成同簇的趋势．对于这样的组态，Mn原子之间为反铁磁耦合能量更低．

We investigate the electronic and magnetic properties of the diluted magnetic semiconductors Zn1-xMnxS（001） thin films with different Mn doping concentrations using the total energy density functional theory. The energy stability and density of states of a single Mn atom and two Mn atoms at various doped configurations and different magnetic coupling state were calculated. Different doping configurations have different degrees of p-d hybridization, and because Mn atoms are located in different crystal-field environment, the 3d projected densities of states peak splitting of different Mn doping configurations are quite different. In the two Mn atoms doped, the calculated ground states of three kinds of stable configurations are anti-ferromagnetic state. We analyzed the 3d density of states diagram of three kinds of energy stability configurations with the two Mn atoms in different magnetic coupling state. When the two Mn atoms are ferromagnetic coupling, due to d-d electron interactions, density of states of anti-bonding state have significant broadening peaks. As the concentration of Mn atoms increases, there is a tendency for Mn atoms to form nearest neighbors and cluster around S. For such these configurations, the antiferromagnetic coupling between Mn atoms is energetically more favorable.