Growth-induced perpendicular magnetic anisotropy and clustering in NixPt1-x alloys

Polycrystalline and epitaxial (1 0 0), (1 10), and (1 1 1)-oriented Ni3Pt, NiPt, and NiPt3 films were deposited over a range of growth temperatures from 80 degreesC to 700 degreesC. Films grown at moderate temperatures (200-400 degreesC) exhibit growth-induced properties similar to Co-Pt alloys: enhanced and broadened Curie temperature, perpendicular magnetic anisotropy and large coercivity. As in Co-Pt, the magnetic properties suggest a clustering of Ni into platelets on the growth surface, as the films are being grown. Unlike Co-Pt, however, NiPt films exhibit a strong orientational dependence of anisotropy and enhanced Curie temperature, possibly resulting from different types of surface reconstructions which affect the growth surface. (C) 2001 Elsevier Science B.V. All rights reserved.