Effect of charge carriers on the magnetic properties of the CdCr2Se4 ferromagnetic semiconductor

摘要

The results of an investigation into how the composition of annealing mixtures influences the Curie temperature of single crystals of the CdCr2Se4 ferromagnetic semiconductor are reported. The mechanism of doping of single crystals is analyzed, and the role played by each of the components of the annealing batch is established. It is concluded that the indirect exchange involving n-type carriers near impurity gallium ions leads to a sharp increase in the phase transition temperature (from 130 to 172 K) of the samples. The dependences of the magnetization of samples with different phase transition temperatures on the temperature and magnetic field are compared.