Phase identification of cobalt ferrite/metal composite thin films using convergent beam electron diffraction

Cobalt ferrite/metal composite thin films with a saturation magnetization ( M-s) of similar to 0.729 Weber m(-2) were prepared by a reactive sputtering method. The M-s of the thin films increased with increasing substrate temp erature. The microstructures of the thin films were identified by a converg ent beam electron diffraction method. For the thin films deposited at high substrate temperatures ( >300 degrees C), CoxFe1-x (x approximate to 0.62) metal alloys were separated from the cobalt ferrite matrix. A cobalt ferrit e phase was determined as CoFe2O4 with a cubic structure (a(0) = 0.839 nm) and a space group of Fd3m, while a metal phase CoxFe1-x (x approximate to 0 .62) with a b.c.c. structure (a(0) = 0.289 nm) and a space group of lm3m. ( C) 1998 Kluwer Academic Publishers.