An original route for the preparation of hard FePt

Abstract

The preparation of FePt hard magnetic foils by an original procedure is described in this paper. The process associates cyclic co-deformation of Fe and Pt foils down to the nanometer scale (total thickness of multilayer ?? 100 ?m) followed by heat treatment in the temperature range 450-550?C. The formation of the high-anisotropy L10 FePt phase results from controlled diffusion and an ordering phase transformation. Coercivities as high as 0.9 T were measured in a VSM at room temperature following annealing at 450?C for 48 h. The coercivity of this sample was decreased by half when measured at 600 K while its energy product decreased from 100 kJ/m3 at 300 K to 25 kJ/m3 at 600 K. ?? 2002 Elsevier Science B.V. All rights reserved.