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

摘要

FePd-alloy epitaxial films were prepared on MgO substrates of (100)_(B1), (110)_(B1), and (111)_(B1) orientations at a temperature of 600 °C by ultrahigh vacuum rf magnetron sputtering. The structural and the magnetic properties vary depending on the substrate orientation. L1_0-FePd(001) films are obtained on MgO(100)_(B1) substrates, whereas L1_0-FePd(101) films with the c-axis canted from the perpendicular direction are epitaxially grown on MgO(111)_(B1) substrates with six variants. FePd epitaxial films consisting of L1_0(100) and L1_0(112) crystals are formed on MgO(110)_(B1) substrates. A higher long range ordering parameter is obtained on the order of FePd/MgO(100)_(B1) >(110)_(B1) >(111)_(B1). The films grown on MgO(100)_(B1) substrates show perpendicular magnetic anisotropy, whereas the films grown on MgO(110)_(B1) and MgO(111)_(B1) substrates are easily magnetized in in-plane directions. The magnetization properties reflect the magnetocrystalline anisotropics of bulk L1_0-FePd crystal.