INFLUENCE OF STRESS AND MICROSTRUCTURE ON THE DOMAIN DISTRIBUTION IN SPUTTERED COFE FILMS

•Jeffrey McCord1, Sascha Dieter2 und Klaus Seemann3
1Leibniz Institute for Solid State and Materials Research, Helmholtzstrasse 20, 01096 Dresden
2TU Berlin Institut für Werkstoffwissenschaften Ernst-Reuter-Platz 1, 10587 Berlin
3Forschungszentrum Karlsruhe Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen

Mixed domain states in rf-sputtered CoFe films were observed by Kerr microscopy. The coexisting domain patterns were distinguished from each other by digital image processing in the frequency regime. Two congruent mechanisms were found to be responsible for domain structures. First, a magnetoelastic induced magnetic anisotropy component introduced by the compressive stress in the films. This contribution diminishes with reduced stress in the films. Furthermore, contributions from the microstructure of the film are observed. A (110)-fiber texture together with the magnetocrystalline anisotropy of the films leads to additional anisotropy components aligned partially out-of-plane to the film surface. Also, grain coarsening due to columnar growth of the films is observed. These microstructural changes result in a patch-like domain pattern, increasing in intensity with film thickness. The connection between stress, texture, and microstructure on domain distribution is discussed in detail.