Growth and characterization of epitaxial $FexPt100−x$ films on MgO(111)

$FexPt100−x$ films were grown on MgO(111) by co-sputtering Fe and Pt. Composition of the films was determined by Rutherford backscattering spectrometry with an accuracy of 1%. Epitaxy and alloy ordering were quantified by x-ray diffraction and the order parameter was determined to be 0.97 for a film with $x=30$ and 0.99 for a film with $x=25$⁠. Neutron diffraction measurements established the presence of an antiferromagnetic phase at $T=100K$ in 500 nm $FePt3$ samples grown on MgO(111). Since $FePt3$ can be grown as an ordered antiferromagnet and a disordered ferromagnet, these films provide a pathway to grow lattice matched interfaces for exchange bias studies.