Magnetic, optical, and electrical properties of solid solutions VxFe1−xBO3

Abstract

Complex studies of magnetic, electrical, and optical properties of V x Fe 1− x BO 3 solid solutions are carried out in the entire range of concentrations between the extreme compounds VBO 3 and FeBO 3 . A concentration semiconductor-insulator transition accompanied by a change in the magnetic structure is observed. It is found that the physical properties of the solid solution under investigation differ from those predicted in the model of a virtual crystal in the form of an aggregate of V and Fe centers taken with the weight of x and 1− x , respectively. The systems of electron energy levels of the VB 6 O 6 and FeB 6 O 6 clusters are calculated from first principles using the Hartree-Fock method. The calculated electron structure forms the basis for simulating the optical absorption spectra, which are in good agreement with experimental results. A qualitative explanation is given for the entire body of data on electrical conductivity and magnetization.