Effects of bath temperature on electrodeposited permanent magnetic Co-Pt-W(P) films

Abstract

The effects of bath temperature on electrochemical behavior, alloy composition, crystallographic structure, morphology and the magnetic properties of electrodeposited Co-Pt-W(P) films were investigated. Electrochemical studies show that alloy electrodeposition has been shifted to more positive potentials and the critical time for nucleation decreased as electrolyte temperature increased. As the temperature increased from 40°C to 80°C, tungsten content in the deposit increased, while phosphorus content decreased. The films deposited at T = 40°C exhibited soft magnetic properties. However, electrodeposited at T = 70°C, the films exhibited hard magnetic properties. It is also demonstrated that higher temperature more than 70°C could weaken hard magnetic properties. XRD results indicated that the deposits obtained at 50°C-70°C showed enhancement of [00.1] P.O. (preferred orientation) with the bath temperature, which resulted in the stronger perpendicular magnetic anisotropy.