Magnetic and other properties and sputtering behavior of Co-base amorphous alloy films

Abstract

Magnetic and other properties of Co-base amorphous alloy films prepared by sputtering are investigated. A detailed magnetic phase diagram with saturation magnetic flux density, crystallization temperature, and zero-magnetostrictive line on Co-Ta-Zr amorphous alloys were obtained, and the technical knowhow to make a film with well-reproducible characteristics by widely changing the sputtering conditions was related with these physical properties. Especially on alloy sputtering, a phenomenological model for elucidating a composition difference between film and target is presented. After these studies, the film characteristics of Bs=12 kG, Tx=450 °C, ‖λs‖<10−8, Hc<10 mOe, and permeabilities of μ(1 MHz)=7000, μ(100 MHz)=2000 for the single film of 2 μm in thickness and of μ(1 MHz)=4000, μ(100 MHz)=800 for the insulator-sandwiched multilayered film of 10 μm are obtained, and these well-balanced values enable us to apply the materials for high-frequency recording head.