STRUCTURAL AND MAGNETIC-PROPERTIES OF SEMIEPITAXIAL CO CR MULTILAYERS

The structural and magnetic properties of semiepitaxial Co/Cr multilay ers have been studied using reflection high-energy electron diffractio n (RHEED), nuclear magnetic resonance (NMR), and vibrating-sample magn etometry (VSM). A detailed analysis of the RHEED patterns observed dur ing the growth shows that the Cr layers essentially consist of three t ypes 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 us ing diffused-interface models we obtain the average concentration and magnetization profiles in the interfaces which are found to be 5 monol ayers thick. The large intermixing is confirmed by a strong decrease o f the measured saturation magnetization values as the Co-layer thickne ss 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.