1994 Volume 18 Issue S_1_PMRC_94_1 Pages S1_15-18
Highly c-axis oriented, single crystal films of Co1-xCrx (0≤x‹0.3) have been grown epitaxially on mica substrates by e-beam evaporation. The orientation relationship is basically (00.1)mica || (00.1)underlayer || (00.1)Co, and [11.0]mica || [10.0]underlayer || [10.0]Co. Films grown on Ru underlayers have an average grain size of 50-80nm, negligibe fcc content and very narrow c-axis dispersions (Δθ∼0.7-1.5°). For Co films (x=0), the as-grown magnetization structure are mainly 180° domain walls with a uniform distribution of cross-ties for thinner samples (≤300 Å), whilst thicker (› 400Å) ones show stripe domains. These images were analysed in detail to measure the wall widths and associated energy densities for as-grown, remanent and ac-magnetised samples. As expected, the magnetic properties of these films are composition dependent. However, for any Cr concentration, these films exhibit the largest saturation magnetisation when compared with either sputtered or evaporated samples. This enhancement can be attributed to a nanometer-scale segregation of Cr, which in these samples, could be particularly aided by the diffusion on the close-packed planes of the films with very narrow c-axis dispersions. Preliminary x-ray microanalysis and NMR data support this interpretation.