STRUCTURAL AND MAGNETIC-PROPERTIES OF SEMIEPITAXIAL CO CR MULTILAYERS

The structural and magnetic properties of semiepitaxial Co/Cr multilayers have been studied using reflection high-energy electron diffraction (RHEED), nuclear magnetic resonance (NMR), and vibrating-sample magnetometry (VSM). A detailed analysis of the RHEED patterns observed during the growth shows that the Cr layers essentially consist of three types of distorted bcc (110) crystallites, one of them corresponding to the Nishiyama-Wassermann epitaxial relationship and the others to the Kurdjumov-Sachs one. From the resonance frequency of the NMR spectra main line we deduce the close-packed structure of the Co layers and using diffused-interface models we obtain the average concentration and magnetization profiles in the interfaces which are found to be 5 monolayers thick. The large intermixing is confirmed by a strong decrease of the measured saturation magnetization values as the Co-layer thickness decreases and is supposed to be responsible for the deviation from linearity, observed at small thicknesses, in the plot of the effective anisotropy per unit area versus Co-layer thickness.