材料期刊网

In this paper, a simple and uniform expression for calculating the anisotropy of the g factor (characterized by DELTAg = g(perpendicular-to) - g(parallel-to)) for 3d(n) ions in the tetragonal phase of the perovskite structure from the spin-lattice coupling coefficients F11 and F12 in the cubic phase has been proposed by introducing a release factor k. From this expression, the values of DELTAg for Ni2+(3d8) and Ni3+ (3d7) ions in the tetragonal phase of a SrTiO3 Crystal are studied. It is found that for SrTiO3:Ni2+, the observed isotropy of the g factor (DELTAg = 0) is due to the too small value of (F11 - F12) and for SrTiO3: Ni3+, the contribution to DELTAg from the elongation of the octahedron around the Ni3+ ion is important in the case of T near the transition temperature T(c).