A hexagonal ferrite element comprising a hexagonal ferrite film layer and a substrate for supporting the ferrite layer is prepared by applying on the substrate a metal-ion solution comprising an iron (II) ion and at least one ion selected from the group consisting of Ba.sup.2+, Sr.sup.2+, Pb.sup.2+, La.sup.3+ and Ca.sup.2+, with the pH of the solution set at 7 or more, thereby oxidizing the iron (II) ion contained in the metal-ion solution to iron (III) ion. For controlling the magneto-optical characteristics of the produced hexagonal ferrite film, other ions such as Co.sup.2+, Co.sup.3+, Al.sup.3+, In.sup.3+ and Ti.sup.4+ may be added to the above metal ion solution, thereby replacing part of iron atoms contained in the ferrite film by such atoms added in the form of ion. Further, for a more controlled and efficient production of the ferrite film, an oxidizing liquid for oxidizing the iron ion, Fe.sup.2+, contained in the metal-ion solution, to Fe.sup.3+ can be used by supplying the oxidizing liquid to the substrate concurrently with or after the application of the metal ion solution.
The present invention provides a Y-type hexagonal ferrite thin film suitable for high frequency devices, having a crystal structure with the c-axis oriented perpendicular to the surface of the thin film. The present invention also provides a method of producing the Y-type hexagonal ferrite thin film, comprising the steps of preparing a viscous solution containing a metal-organic complex which is formed using a primary component including a Fe.sup.+3 ion, and a secondary component including a Ba.sup.2+ ion, at least one transition metal ion selected from the group consisting of Fe.sup.2+, Co.sup.2+, Ni.sup.2+, Zn.sup.2+, Cu.sup.2+ and Mn.sup.2+; and optionally at least one metal ion selected from the group consisting of Sr.sup.2+, Ca.sup.2+ and Pb.sup.2+, forming a film having a Y-type ferrite composition on a surface made of noble metal through a coating process using the viscous solution, and burning the film at a temperature of 750.degree. C. or more.
A high-density recording media comprising longitudinally oriented polycrystalline barium ferrite exhibits large coercivity, corrosion resistance, high hardness and durability. Films are prepared by on-axis sputtering at ambient temperatures from stoichiometric targets followed by a post-deposition anneal at approximately 850.degree.C. to induce crystallization. Crystallization yields a magnetic film with large in-plane remanence and a fine scale texturing that greatly improves the tribological performance of barium ferrite disks. Exceptional durability can be achieved on disks without overcoats. Grain sizes as small as 200 .ANG. are produced by doping with small amounts of Cr.sub.2 O.sub.3 or other additives. Coercivities greater than 4000 Oe are achieved even in small grain films.
A ferrite layer formation process that may be performed at a lower temperature than conventional ferrite formation processes. The formation process may produce highly anisotropic structures. A ferrite layer is deposited on a substrate while the substrate is exposed to a magnetic field. An intermediate layer may be positioned between the substrate and the ferrite to promote bonding of the ferrite to the substrate. The process may be performed at temperatures less than 300.degree. C. Ferrite film anisotropy may be achieved by embodiments of the invention in the range of about 1000 dyn-cm/cm.sup.3 to about 2.times.10.sup.6 dyn-cm/cm.sup.3.
A thick film complex electronic component mounted on a substrate including an inductance, capacitance and/or resistance by a conductive film and a magnetic film on a ceramic substrate is improved by novel magnetic film. The magnetic film is produced by depositing paste of a raw material of ferrite on the substrate, and the paste together with the substrate are sintered at a relatively low temperature in the range of 600.degree. C. and 1200.degree. C. The present magnetic film which is sintered after the raw material of ferrite is deposited on the ceramic substrate has higher permeability and is mechanically stronger.
A method for making ferrite powder may include providing ferrite feed materials in a form of particles having different sizes and irregular shapes, and exposing the ferrite feed materials to a plasma to provide a more spherical shape to irregularly shaped particles to thereby make the ferrite powder. An apparatus for making ferrite powder may include a feeder for ferrite feed materials and a plasma generator for exposing the ferrite feed materials to a plasma.
