Theoretical investigation of the local lattice structure of Cr2+ ion at tetragonal sites in GaAs semiconductor

An analyses of the relationship between the experimental zero-field splitting (ZFS) parameters D, a, F and the local lattice structure of Cr2+ ion located at tetragonal site in GaAs semiconductor is presented on the basis of the complete energy matrix for the d4 configuration in a tetragonal ligand-field within strong-field representation. Our results show that there exists an expansion distortion in the local lattice structure. From our calculations, the distortion parameters ΔR = 0.045 Å and Δθ = 2.53° for GaAs:Cr2+ system are determined.