Magnetic structure and magnetoresistance of patterned epitaxial iron thin films: The influence of shape and magnetocrystalline anisotropy

A magnetic-force-microscopy investigation is conducted into the influence of the shape and magnetic anisotropy on the magnetic structure and the mode of magnetization reorientation in epitaxial iron thin films patterned by subtractive techniques. Magnetic anisotropy is found to have a strong influence on the magnetic structure. With an applied field directed along a specimen, the latter is in a single-domain state when oriented parallel to the easy axis of magnetization, and is in a multidomain state when oriented perpendicular to the easy axis, the domain magnetic moments being parallel to the easy axis in both cases. The magnetic structure appears as a streaky pattern. Magnetization reorientation proceeds by domain-wall motion in both cases. The tanks do not change the mechanism of magnetization reorientation in the rectangular part, yet they ensure a single-domain state at lower magnetic flux densities. The results should offer some scope for using epitaxial iron thin films of suitable shape and crystallographic orientation in spin-valve injectors or detectors. © 2008 MAIK Nauka.