Chemical vapor deposition of epitaxial garnet films

The chemical vapor deposition of single crystal metal oxides has recently been extended to the growth of certain epitaxial garnets, in particular YIG on YAG and GdIG on YAG. The light green, transparent films are
\sim3\mu
thick and are limited in area only by the area of the available YAG seeds. On (100) seeds, the YIG deposits display tiny fingerprint-type magnetic domains as revealed by Bitter patterns and by the Faraday magneto-optic effect; this is in contrast to manganese ferrite films of similar thicknesses which have very large domains in which the magnetic vectors assume the (110) secondary easy axis in the plane of the film. The growth method involved the high temperature hydrolysisoxidation of the mixed vapors of the pertinent metal halides at the seed surface. The necessary conditions for single crystal growth are compared to those for other metal oxides, in particular the ferrites. The present state of characterization of the films with respect to composition, quality, and magnetic properties is presented.