US 4,269,651 A · Process for preparing temperature-stabilized low-loss ferrite films

Abstract

In the preferred embodiment, a monocrystalline film of substituted yttrium iron garnet (YIG) deposited on a <111> oriented gadolinium gallium garnet (GGG) substrate is formulated so that the temperature variation of the ferromagnetic resonance frequency of the film has an ordinary minimum. For a range of temperature variations about the temperature at which the minimum occurs, therefore, the resonance frequency of the film is relatively insensitive to variations in temperature. This minimum is believed to occur where the temperature variations of the demagnetizing effect and the temperature variations of anisotropy effects more or less counterbalance each other. The counterbalancing effects are brought within range of each other primarily by the substitution of gallium or aluminum for iron and the substitution of lanthanum for yttrium in the substituted YIG. Gallium or aluminum reduces the temperature drift of the saturation magnetization. Lanthanum adjusts the misfit stress and thus the anisotropy effects.

Claims6

Dependent claims

A method of forming a composite structure exhibiting loss loss microwave or millimeter-wave ferromagnetic resonance, said method comprising the steps of:

(a) providing a single-crystal substrate, wherein said substrate is of a material selected from the group consisting of the rare-earth gallium garnets, the mixed rare-earth gallium garnets, the rare-earth aluminum garnets, the mixed rare-earth aluminum garnets, magnesium oxide, the gallate spinels, the indium-gallate spinels, the aluminate spinels, and sapphire;
(b) forming a monocrystalline film of a ferrimagnetic material on said substrate by a controlled deposition process wherein said ferrimagnetic material is selected from the group consisting of garnet-structured ferrites, spinel-structured ferrites, hexagonal ferrites, and orthoferrites;
(c) measuring the variation of ferromagnetic resonance frequency of said film with variations in temperature;
(d) determining from the measurements a temperature at which the variation of ferromagnetic resonance frequency exhibits an ordinary extremum;
(e) varying parameters of said controlled deposition process and repeating steps (a) through (d) until said temperature at which the variation of ferromagnetic resonance frequency exhibits an ordinary extremum is substantially the same as a preselected temperature.

2 more elements

Dependencies are inferred from the claim text.

Process for preparing temperature-stabilized low-loss ferrite films

Life of this patent

Process for preparing temperature-stabilized low-loss ferrite films

Life of this patent

Abstract

Claims6