STRUCTURAL AND MAGNETIC-PROPERTIES OF NI CR MULTILAYERS/

Ni/Cr multilayers have been grown on Si(100) by de triode sputtering. Three different samples have been investigated where the only purposel y variable parameter is the superperiod: Lambda = 52, 35 and 27 Angstr om. The Ni:Cr ratio was kept constant equal to 1:1 and the total thick ness is about 1200 Angstrom. The quality of the layering is shown by t he low-angle X-ray diffraction spectra which exhibit both thickness fr inges and Bragg peaks. At large angles, weak superlattice peaks appear around the 110(Cr)/111(Ni) diffraction peak. Pole figure measurements indicate a fiber texture: [111] for Ni and [110] for Cr. The average stress in the stackings has been evaluated via curvature measurements: the samples are in a high state of compressive stress, larger than I GPa. Systematic magnetization measurements have been performed with a vibrating sample magnetometer as a function of temperature with the ap plied field parallel or perpendicular to the sample plane. All the mul tilayers exhibit in-plane anisotropy. The magnitude of the saturation magnetization indicates an important Ni-Cr intermixing at the interfac es. The temperature behaviour of the magnetic moment indicates two-dim ensional effects.