Magnetic devices utilizing garnet epitaxial materials

摘要

Members of a class of garnet compositions of particular crystallographic orientation are usefully incorporated in magnetic memory devices which depend for their operation on the positioning of single wall domains ("bubbles"). Such compositions, ordinarily in the form of a supported layer defining a (110) orientation, manifest high limiting bubble velocity, thereby making possible high record and retrieval rates. Compositions invariably contain some lanthanum in the dodecahedral site. Increased limiting velocity is attributed to in-plane anisotropy, in turn, dependent upon partial lanthanum occupation. Depending upon composition, required unique easy direction out of the plane may be as-grown, stress induced, or a combination. Appropriate garnet substrates of required lattice parameters are described.