Ferrite Substrate Preparation for High Quality Deposited Films and Preparation of Polycrystalline Ferrite Substrates
Original Publication Date: 1978-Jun-01
Included in the Prior Art Database: 2005-Feb-21
There are many instances where it is desirable to obtain an extremely smooth, flat surface. One such instance is in the preparation of a ferrite substrate on which thin permalloy films are to be deposited for magnetic heads. Even minute scratches or other surface imperfections on the ferrite substrate can cause erratic behavior of the permalloy film, such as Barkhausen noise. The magnetic properties are also somewhat improved by minimizing imperfections on the surface of the substrate. Additionally, with purely mechanical polishing techniques for obtaining a smooth surface, a "dead layer," i.e., a nonmagnetic layer of ferrite, is formed on the surface, which layer is undesirable in certain applications.