中文摘要：

基于密度泛函理论的第-性原理,采用全势线性缀加平面波方法（FPLAPW）和广义梯度近似（GGA）来处理相关能,计算了n 层过渡金属Cr掺杂SnO2 超晶格的电子态密度、能带结构和光学性质（n=1,2,3）.结果表明,掺杂使材料均表现出了半金属性,并且导电性和磁矩随着n 的增大而增强.掺杂后材料磁矩主要来源于Cr3d态,Cr的加入使O 的态密度产生了自旋极化现象.在0～1.8eV 处掺杂所形成的第一吸收峰的位置随着n 的增加而向高能方向推移,在1.8～7.0eV 处所形成峰的峰值随着n 的增大而增加,在7.0～17.0eV 处所形成的峰的峰值随着n 的增大而减小.

英文摘要：

The density of state （DOS）,band structure,optical coefficient of n-layers transition metal Cr doped SnO 2 superlattice were calculated using first-principles of density functional theory and full potential linearized augmented plane wave method （n=1,2,3）.Generalized gradient approximations （GGA）were used for han-dling correlation energy.The result show that doped SnO 2 are half-metallic.The magnetic moment and electro-conductivity will be enhanced with the increase of n .The magnetic moment was contributed mainly by Cr3d states.The doping-Cr makes the DOS of oxygen producing spin polarization.In 0-1.8 eV,the position of first absorption peak will move to higher energy region with the increase of n .In 1.8-7.0 eV,the magnitude of the peak was augmented with the increase of n .In 7.0-17 eV,the magnitude of the peak was reductive with the in-crease of n .