Preparation of novel potassium, lanthanum-iron oxides and their magnetic properties

抄録

We have investigated the synthesis conditions, and the magnetic properties of M-type ferromagnetic potassium, lanthanum-iron oxides. The samples were prepared by solid-state-reaction. It is found that a new M-type ferrite can be effectively synthesized at 1275°C from the starting materials pulverized with a planetary ball mill. The magnetic transition temperature of the sample is 440°C which is quite close to that of the magnetoplumbite-type ferrite. EPMA compositional analysis for this new M-type ferrite shows the composition ratio of K : La : Fe = 0.75 : 0.90 : 18.58. From this result, the chemical formula of the magnetoplumbite phase in this sample is estimated to be K_0.45La_0.55Fe₁₂O_19-δ.