Magnetic domains in Co thin films obliquely sputtered on a polymer substrate

Magnetic domains in obliquely sputtered Co films on a polymer substrate have been investigated with magnetic force microscopy. The growth angle has been found to strongly affect the domain structure as well as the magnetic properties, due to changes in the microstructure. At large angles finite-size elongated domains oriented in the longitudinal direction ~projection of the growth direction on the film plane! were energetically favorable. However, at intermediate angles a transition to stripe domains occurs due to an increase in exchange coupling. These domains exhibit a width of 400 nm and lie along the longitudinal direction. In the remanent state ~after saturation!, circular as well as elliptical magnetic bubbles coexist, but coalesce in the dc demagnetized state to form stripe domains.