Improvements in the Corrosion Resistance of Acicular Fe4N Particles for Magnetic Recording Tape

Abstract

The effects of thermal surface-oxidation and Ni addition on the corrosion resistance and magnetic properties of acicular Fe₄N particles were studied. The corrosion resistance was evaluated by measuring the loss-rate of saturation magnetization in a humid air (90% R. K)at 60°C in 75 h. The surface-oxidation improved the corrosion resistance but concomitantly the saturation magnetization deereased, while the Ni addition improved the corrosion resistance to a small extent. However, combination of surface-oxidation and Ni addition led to high stabilization and high saturation magnetization to Fe4N particles. The corrosion resistance of magnetic tapes fabricated with these particles was comparable to that of commercial 8 mm video tapes.