TEMPERATURE-STABILIZED LOW-LOSS FERRITE FILMS

摘要

TEMPERATURE-STABILIZED LOW-LOSS FERRITE FILMS 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.