摘要
Electronic structure and magnetic properties of Cu_(0.5)Zn0.5Cr_(2)S_(4),Cu_(0.5)Cd_(0.5)Cr_(2)S_(4), Li_(0.5)Zn_(0.5)Cr_(2)O_(4) and Li_(0.5)Zn_(0.5)Cr_(2)S_(4) are investigated using the first-principles calculation based on the density functional theory.GGA +U exchange correlation is used in the calculation to correct the effective Coulomb repulsion energy of Cr underestimated by LSDA or GGA.The calculation results reveal that half-metallic Cu_(0.5)Zn_(0.5)Cr_(2)S_(4) and Cu_(0.5)Cd_(0.5)Cr_(2)S_(4) can be achieved by doping CuCr_(2)S_(4) with Zn or Cd,though CuCr_(2)S_(4) is not half-metallic.Half-metallic LiCr_(2)O_(4) is experimentally unstable,but half-metallic Li_(0.5)Zn_(0.5) Cr_(2)O_(4) and Li_(0.5)Zn_(0.5) Cr_(2)S_(4) can be achieved by doping Li into experimentally stable ZnCr_(2)O_(4) and ZnCr_(2)S_(4),though ZnCr_(2)O_(4) and ZnCr_(2)S_(4) are not half-metallic.The influence of +U on the electronic structure and half-metallicity of the doped systems is also presented.
基金
Supported by the National Natural Science Foundation of China under Grant Nos 10974099
the National Basic Research Program of China under Grant No 2011CB606405
the Fundamental Research Funds for the Central Universities of China under Grant No 65012031。
作者简介
Correspondence author:刘志强,Email:liuzhiqiang216@gmail.com。
