MAGNETIC-PROPERTIES OF NI/PT MULTILAYERS

We have grown Ni/Pt multilayers (ML) with and without Pt buffer layer, by evaporation under UHV conditions on glass and Si substrates maintained at 30 and 200-degrees-C. The magnetization decreases with t(Ni) and no induced moment is found on Pt from polarization effects even at 5 K. The perpendicular magnetization loops for samples with t(Ni) less-than-or-equal-to 17 angstrom are rectangular and coercivities as high as 4.7 kOe is obtained for t (Ni) = 9 angstrom at 5 K. For the samples deposited at 20-degrees-C, due to dispersion in the results, K(S) could not be calculated with accuracy though it is positive. But for the samples deposited on a Pt buffer layer at 200-degrees-C, K(S) is found to be +0.17 erg cm-2 at 5 K and the volume anisotropy is also higher with respect to those deposited at 30-degrees-C.