Observation of perpendicular magnetic anisotropy in Ni/Pt multilayers at room temperature

Abstract

We report the experimental observation of room-temperature perpendicular magnetic anisotropy in Ni/Pt multilayers having 7-26 Angstrom Ni and 2.3-4.6 Angstrom Pt layer thicknesses, prepared by dc magnetron sputtering on glass substrates at 7 mTorr Ar sputtering pressure. Perpendicular magnetic anisotropy was found to be sensitively dependent on both Ni- and Pt-layer thicknesses, and a maximum anisotropy energy of 1.74x10(5) erg/cm(3) was obtained for (16 Angstrom Ni/2.3 Angstrom Pt)(30) multilayer. Interestingly, magnetization measurements revealed that about two atomic layers of Ni at the interface were magnetically dead in our samples. (C) 1998 American Institute of Physics.