Domain Structures in Epitaxially Grown Cobalt Thin Films

Following the epitaxial growth and characterization of single crystal c-axis oriented hcp cobalt thin films (with thicknesses in the range of 200–600 Å), we have investigated their micromagnetic domain properties by Lorentz electron microscopy (LEM). In particular we have used the differential phase contrast mode of LEM because this imaging technique allows a wide range of quantitative analysis to be carried out directly. The domain structures were studied in the as-grown, ac-demagnetized and remanent states. Large domains with regular magnetization ripple and cross ties were observed in the thinner films, whilst stripe domains were seen in films with thicknesses ≥ 400 Å. Detailed analysis of the DPC images led to information pertaining to the domain wall width and its associated energy density being attained.