Effect of diamagnetic substitutions in BaFe12O19 on the magnetic properties

The exchange parameters of BaFe₁₂O₁₉ have been calculated from the temperature dependence of the saturation magnetization using the molecular field theory. Under the assumption that the exchange parameters do not change for diamagnetic substitutions of the Fe³⁺ ions, it is shown that the temperature coefficient of the magnetization at room temperature cannot be decreased without decreasing the magnetization. Diamagnetic substitution in the octahedralf ₂ site would solely increase the saturation magnetization.