Observation and analysis of mixed domain states in sputtered Co50Fe50 films

Abstract Mixed domain states in sputtered Co 50 Fe 50 films were observed by Kerr microscopy. Coexisting domain patterns of different origin were found. Low- and high-pass image filtering in the frequency regime was used to separate the congruently occurring stripe and patched domain patterns from each other. Two mechanisms are responsible for the domain development. Firstly, a magnetoelastically induced magnetic out-of-plane anisotropy component introduced by compressive stress in the films, diminishing with reduced stress amplitude in the films. Differences between calculated and observed occurrence of stripe domains are explained with a thickness dependant stress distribution in the films. Secondly, additional contributions on the domain formation from the microstructure of the films are observed. A (1 1 0)-texture, together with the magnetocrystalline anisotropy of the films, leads to additional anisotropy components relevant for the domain configuration. Furthermore, grain coarsening with increasing thickness due to columnar growth of the films is observed. The microstructural characteristics lead to a patch-like domain pattern, decreasing in size with film thickness. A direct connection between stress, texture, and microstructure on domain distribution is made.