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,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(Cu Cl和Cu Br)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Cu Cl产生稳定的半金属铁磁性,随着压强的增大Cu Cl0.75N0.25和Cu Cl0.75O0.25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 possibilities of half- metallic ferromagnetism in cuprum halides （CuC1 and CuBr） with nonmag- netic sp elements C, N and 0 as dopants have been explored using the first principles plane wave pseudo poten- tial method based on density functional theory （DFF） in combination with the generalized gradient approximation （GGA）. We investigate the electronic structure and magnetic properties in cuprum halides doped with non-mag- netic 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 re- veal that O- and N-dopants can induce a stable ferromagnetic state in CuC1, and that its ferromagnetism decreases and finally a magnetic phase transition from ferromagnetic （FM） to nonmagnetic （NM） phase occurs with the in- creasing pressure.