STRUCTURAL CHARACTERIZATION OF EPITAXIAL CO-AG

Co-Ag granular films are prepared by molecular-beam epitaxy to enable a detailed structural study to be conducted in conjunction with magnet otransport properties. It is demonstrated that the shape, size, locati on, and segregation of the magnetic Co grains and the morphology of th e surface depend on the growth temperature. Detailed transmission elec tron microscopy reveals inherent differences between samples prepared at room temperature and those prepared at high temperature. Small clus ters of only a few atoms are found to be present in the matrix of the low-temperature samples significantly affecting the spin diffusion len gth. Well-crystallized regions of both Co and Ag are found in the high -temperature samples, however, the Co grains remain relatively small i n size even at the highest growth temperatures. (C) 1996 American Inst itute of Physics.