Optimum Conditions for Synthesizing Fe Substituted Hibonite

Abstract

We investigated the synthesis conditions and magnetic properties of Fe substituted hibonite with initial compositions of CaAlxFey−xO19−δ (1 ≤ x ≤ 3, 5 ≤ y ≤ 9) and CaAlxFe8-xO19−δ (0.5 ≤ x ≤ 1.6) sintered at 1200-1300ºC. The optimum conditions for synthesizing the best magnetic hibonite were found to be the initial composition of Ca:Al:Fe = 1:0.6:7.4 and the sintering temperature of 1250ºC. The best magnetic hibonite was magnetized at 75.0 A·m 2 /kg at T = 5 K and µ0H = 7 T. This magnetic moment can be interpreted with a model of the collinear magnetic structure. The Curie temperature of the best magnetic hibonite was 330ºC, which was the highest among those of iron-substituted hibonite samples.