Effect of oxygen deficit on magnetic properties of LaCo0.5Fe0.5O3

LaCo0.5Fe0.5O3+d system has been prepared using different thermal treatments by conventional ceramic technology. The samples prepared at 1570 K in air and below this temperature are mixtures of orthorhombic and rhombohedral phases. Increasing temperature up to 1670 K stabilizes the rhombohedral phase whereas annealing in vacuumed quartz tube with a metallic getter results in orthorhombic single-phase structure. All the samples exhibit the ferromagnetic component at temperatures up to 360 K as a result of Dzialoshinsky–Moriya interactions between the Fe3+ ions. The orthorhombic samples have a giant magnetic anisotropy, mostly associated with Co2+ ions. Co3+ ions are supposed to adopt a low spin state.