Magnetic Domain Patterns on Thin Films

Abstract

Magnetic domain patterns have been observed on evaporated films of iron, cobalt, nickel, and several different alloys of these elements. The films were deposited in the presence of a magnetic field to establish a uniaxial direction of easy magnetization. It was found that the direction of easy magnetization, in films of all compositions, could be changed by re-heat-treating them in a magnetic field with a new orientation. This is of special interest because bulk specimens of the elements do not respond to heat treatment in a magnetic field. Nucleation and growth of domains were observed for fields applied at various angles to the uniaxial direction of easy magnetization in some of the films. Patterns were obtained on films ranging in thickness from approximately 50 A to 12 000 A. Domain walls in films ranging from 50 A to 500 A in thickness tend to aggregate in pairs.