Synchrotron X-ray diffraction measurements of the FCC/FCT phase transformation in PtMnCr pinning layers

Abstract

We examine the change in structure of the pinning layer of PtMnCr/NiFe bilayers in the as-deposited state and upon annealing, using synchrotron radiation. The X-ray measurements show that the degree of transformation of the FCC phase of PtMnCr to the antiferromagnetic FCT phase increases with annealing time. Although a slightly higher amount of the FCT(1 1 1) planes grow at 0°, 25° and 45° with respect to the surface, it is apparent that the re-orientation and growth of the FCT phase is predominantly random. These structural effects are discussed in terms of their effect on the magnetic properties.