FePt fct-[001] texture prepared at lower temperature for perpendicular recording

Summary form only given. FePt thin films with L1/sub 0/ ordered structure (fct-phase) attract high attentions due to their possible use as ultrahigh density recording media. For perpendicular recording, it is essential to have films with the fct-[001] orientating perpendicular to the film plane. Previous study by the authors (IEEE Trans. Magn. vol.37, p.1491-3 (2001)) indicated that addition of Ru to Cr favors to realize Cr[200] orientation. In this paper, an CrRu underlayer with [200] texture is used to control the FePt orientation. It is expected that the FePt fct-[001] texture can be epitaxially grown with crystallographic relationship Cr[200][110]//FePt[001][100]. On the other hand, the expansion strain along the FePt a-axis in the interface may be preferred to transform the fcc to the fct phase. We change the Ru content in Cr to vary the lattice mismatch between the FePt layer and underlayer, in expectation of strain-induced preferred phase transformation and lowering the ordering temperature.