Composition dependence of fundamental properties of $$hbox {Cd}_{mathrm{1-x}}hbox {Co}_mathrm{x}$$Te magnetic semiconductor alloys

Ab initio calculations based on density functional theory have been performed using the full-potential augmented-plane-wave method so as to investigate the composition dependence of the electronic structure and fundamental properties of hypothetical zinc-blende (hbox {Cd}_{mathrm{1-x}}hbox {Co}_{mathrm{x}}hbox {Te}) magnetic semiconductor alloys at low Co concentrations. To treat the exchange and correlation energies, the generalized gradient approximation (GGA) of Perdew–Burke–Ernzerhof has been used. In addition, the modified Becke–Johnson exchange potential with the GGA approach is used for the band structure providing high accuracy. It is found that the addition of a small amount of Co atoms in the (hbox {Cd}_{mathrm{1-x}}hbox {Co}_{mathrm{x}}hbox {Te}) makes the latter less compressible, ferromagnetic and exhibiting a half metallic character. Besides, the composition dependence of the real and imaginary parts of the dielectric function has been examined and discussed. The information derived from the present study may be useful for spintronics technological applications.