Noncubic magnetic anisotropies in bulk and thin-film garnets

Abstract

Magnetic bubbles have been reported in bulk grown, chemical vapor deposition (CVD), and liquid phase epitaxy (LPE) garnets, implying the existence of noncubic anisotropies in all of these materials. Anisotropy magnitudes, directions, nonuniformities, and annealing behaviors and effects of strain relief on the anisotropies of several potentially useful garnet materials are presented and compared. These observations indicate that the noncubic anisotropies in the bulk materials and LPE films are similar, and are consistent with the pair-ordered model. Annealing reduces the growth induced anisotropy of LPE films and may be useful for increasing wall mobility, decreasing coercivity, and altering bubble sizes to match circuits.