Suppression of growth-induced perpendicular magnetic anisotropy in Co-Pt alloys by trace amounts of Si

(CoxPt1-x)(1-y)Si-y alloys with Si content from 1 to 20 at. % have been gro wn over a range of growth conditions. Co-deposition of even trace amounts o f Si with Co-Pt alloys causes the growth-induced magnetic anisotropy and ch emical clustering found in these vapor-deposited alloy films to decrease or vanish. It also causes significant reduction in grain size. Addition of 5 at. % Si eliminates anisotropy completely. Addition of 1 at. % Si produces a film with magnetic properties identical to pure Co-Pt alloys grown at low er deposition temperatures. We suggest this suppression of anisotropy and r elated effects are due to a decrease in surface mobility during growth in t he presence of even trace amounts of Si. (C) 1999 American Institute of Phy sics. [S0003-6951(99)02352-9].