Epitaxial process of forming ferrite, Fe.sub.3 O.sub.4 and .gamma.Fe.sub.2 O.sub.3 thin films on special materials

A method of depositing magnetic ferrite films on a substrate comprising the sequential steps of:

• placing a substrate having a surface to be coated and comprising a substantially noncrystalline material in an evacuable deposition chamber,
• vacuum depositing a polycrystalline film of a first material having b.c.c. crystal structure characteristics with a 110 texture consisting of a material selected from the group consisting of vanadium and chromium, and
• then epitaxially vacuum depositing magnetic ferrite on said polycrystalline film.

A magnetic thin film ferrite epitaxially deposited upon a substrate coated with an intermediate thin film layer of a metal having a crystal structure with lattice constants yielding crystal structures on the order of about 8.35 .times. 8.35A square, said metal having been deposited by a method selected from the group consisting of evaporation at a pressure on the order of 10.sup.-.sup.6 Torr and sputtering in an inert atmosphere at a pressure on the order of 2 .times. 10.sup.-.sup.2 Torr, and

• then epitaxially vacuum depositing said ferrite on said intermediate layer to form a cubic spinel structure upon said intermediate layer.

A method of forming an epitaxial magnetic ferrite film consisting of at least one of Fe.sub.3 O.sub.4 and .gamma.Fe.sub.2 O.sub.3 comprising the sequential steps of

• sputtering a thin film of a metal selected from vanadium and chromium onto a substrate,
• then vacuum depositing said epitaxial magnetic ferrite film on said film of a metal.

A low temperature method of forming an iron oxide magnetic film of material comprising .gamma.Fe.sub.2 O.sub.3 and Fe.sub.3 O.sub.4 comprising the sequential steps of vacuum depositing a 200A to 10,000A thick metal film of a metal selected from the group consisting of chromium and vanadium on a substrate held at a temperature between 200.degree. and 250.degree. C to form a b.c.c. structure with 110 texture, and

• thereafter sputtering a 100A to 10,000A thick epitaxial layer of magnetic iron oxide at a substrate temperature between 125.degree. to 225.degree. C in an inert gas atmosphere at a pressure of about 2 .times. 10.sup.-.sup.z Torr to form said magnetic iron oxide film on said metal film.