Magnetic properties of cobalt electrodeposited anodic oxide magnetic films

Abstract

Abstract A magnetic film was fabricated by electrodeposition of cobalt in the pores of an aluminum anodic oxide. The dependence of coercive force and magnetic anisotropy energy on the packing density and diameter of the cobalt particles was investigated when the pore diameter was kept constant. The dependence of coercive force on the electrodeposition condition of cobalt was also investigated. The coercive force perpendicular to the film surface decreased when the packing density increased because the c ‐axis, which is the axis of easy magnetization in a cobalt crystal, tended to incline to the film surface direction when the packing density increased. Magnetic anisotropy energy depended strongly on packing density. When the packing density was less than 0.26, the direction perpendicular to the film surface became the axis of easy magnetization. The perpendicular magnetic anisotropy energy was smaller than the calculated value of the magnetostatic energy because of the in‐plane orientation of the c ‐axis. In a magnetic film with a pore diameter of 200 Å, the perpendicular coercive force was varied from 2000 to 1200 Oe by controlling the pH and the temperature of the cobalt electro‐depositing bath.