The magnetostriction contribution of manganese ions in spinel ferrites

The assumption that the magnetostriction contribution from manganese ions in spinel ferrites arises from Mn³⁺ ions has been tested by an ab initio calculation of the theoretical values of the coefficients λ₁₀₀ and λ₁₁₁. The Mn³⁺ contribution on octahedral sites is found to be negligible while the possible contribution from Mn³⁺ ions on tetrahedral sites cannot be fitted to the experimental results. It is possible that the contribution from a small concentration of Mn⁴⁺ ions on tetrahedral sites could give a magnetostriction contribution which fitted both λ₁₀₀ and λ₁₁₁.