Structural and magnetic properties of FePd and CoPd alloy epitaxial thin films grown on MgO single-crystal substrates with different orientations

FePd and CoPd alloy thin films were prepared on MgO single-crystal substrates of (001)B1, (110)B1, and (111)B1 orientations at 600 °C by ultra high vacuum rf magnetron sputtering. L10-FePd(001) films with the c-axis perpendicular to the substrate surface are obtained on MgO(001)B1 substrates. FePd epitaxial films consisting of L10(110) and L10(011) crystals are formed on MgO(110)B1 substrates. The c-axis of L10(110) crystal is parallel to the substrate surface, whereas that of L10(011) crystal is 44° canted from perpendicular direction. L10-FePd(111) films with the c-axis 54° canted from the perpendicular direction are formed on MgO(111)B1 substrates. L10 ordering degree of these FePd films varies depending on the substrate orientation. On the other hand, disordered CoPd thin films of (001)A1, (110)A1, and (111)A1 orientations epitaxially grow on MgO substrates of (001)B1, (110)B1, and (111)B1 orientations, respectively. The magnetization properties of L10 ordered FePd and A1 disordered CoPd thin films are influenced by the crystal structure, the ordering degree, and the film orientation.