Magnetic Characterization of Zone-Refined Rare-Earth Orthoferrite Crystals Grown by the Optical Floating Zone Method

Abstract

High-purity single crystals of Sm 1−x YxFeO 3 (x = 0.7, 0.5, and 0.3) were grown in an optical floating zone furnace. Using the zone refining process concomitantly with floating zone growth, we eliminated the impurity phases detected in the synthesized polycrystalline orthoferrite compounds. The zone refining method is very effective in obtaining samples with high purity, especially when trace impurities have a notable influence on physical properties, such as in the case of Sm 0.5 Y 0.5 FeO 3 . The magnetic characteristics of the grown Sm 1−x Y x FeO 3 crystals with varying Y contents are entirely free of spurious effects from impurities that are present in their ceramic or polycrystalline versions. Consequently, we could detect interesting spin configurations and spin reorientation transitions in these high-purity crystals. Sm 0.5 Y 0.5 FeO 3 shows temperature-dependent exchange bias behavior along the a-orientation, which diminishes beyond the spin reorientation temperature. Consecutive MH loops measurements result in athermal-type exchange bias behavior.