Preparation and Soft-Magnetic Properties of Fe-Co-Ni-Cr Plated Films Having a Single Phase Structure and High Saturation Magnetization

The authors investigated the method of preparation and soft magnetic properties of electrodeposited Fe-Co-Ni-Cr alloy film with high saturation magnetization and a single-phase structure. It was found that Fe-Co-Ni-Cr alloy film with a single-phase fcc structure can be electrodeposited at the cathode in a solution composed of Fe²⁺, Co²⁺, Ni²⁺ and Cr³⁺ ions and with SO4^2- as the count anion, by plating at current densities of more than 30 mA/cm². Film consisting of Fe₄₄Co₁₇Ni₃₆Cr₃ alloy, prepared by the plating method described in this paper, has soft magnetic properties (μ_iHA ≫ 1500, H_cHA ≪ 0.5 Oe, λ_s = 6x10^-6, B_s = 16,800 G) qualifying it for use in HDD thin film magnetic head cores.