C、N、O掺杂CuBr和CuCl的电子结构和磁性的第一性原理研究
First Principles Study of Electronic Structural and Magnetic Properties of CuA (A = Cl and Br) Doped with C, N and O

本文基于密度泛函理论（DFT）结合广义梯度近似（GGA），采用第一性原理的平面波赝势方法，探究非磁性sp元素（C、N和O）掺杂卤化物 (CuCl和CuBr) 是否能诱导产生半金属铁磁性。通过计算体系总能量、能带、态密度和分态密度，分析了非磁性元素掺杂卤化物体系的电子结构和磁性；通过对材料加压，给出了体系铁磁性随压强变化的趋势并作了分析。最后计算显示，O和N掺杂能诱导CuCl产生稳定的半金属铁磁性，随着压强的增大CuCl0.75N0.25和CuCl0.75O0.25 的铁磁性减弱最终发生磁相变由铁磁态(FM) 转变为非铁磁态(NM)。
The possibility of half-metallic ferromagnetism in cuprum halides (CuCl and CuBr) with nonmagnetic sp elements such as C, N and O as dopants have been explored using the first principles plane wave pseudo potential method based on density functional theory (DFT) in combination with the generalized gradient approximation (GGA). We investigate the electronic structure and magnetic properties in cuprum halides doped with non-magnetic elements by calculating the total energy system, energy band, the density of states and partial density of states. There gives the analysis of the change of magnetic moments as a function of pressure. Our calculations reveal that O- and N-dopants can induce a stable ferromagnetic state in CuCl, and that their ferromagnetism decreases and finally magnetic phase transition occurs from ferromagnetic (FM) to nonmagnetic (NM) phase with the pressure increased.