Abstract: In the preferred embodiment, a monocrystalline film of substituted yttrium iron garnet (YIG) deposited on a <11> 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 counter-balancing effects are brought within range of each other primarily by the substitution of gallium or aluminum for iron and 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.

Abstract: In an improved bubble lattice file (BLF) structure, two adjacent layers of magnetic bubble domain material are utilized to provide separate media for supporting carrier bubbles or coded bubbles. The coded bubbles, in one layer, represent data stored in the bubble lattice file. The carrier bubbles, in another layer, are magnetically coupled to the coded bubbles and are used in manipulation thereof. The magnetic bubble domain layers may be separated by an appropriate interface layer or surface. The lattice file area, or storage area, is biased by a single layer of bias material while adjacent areas, such as an input/output region, include a pair of biasing layers disposed on opposite sides of the adjacent layer structure. This composite permits an improved bubble lattice file structure which utilizes the storage capabilities of bubble lattice file memories as well as the operating capabilities of so-called conventional magnetic bubble domain device techniques.