Structural and magnetic studies of Fe x Co1− x (001) alloy films on MgO(001) substrates
1995; American Institute of Physics; Volume: 77; Issue: 3 Linguagem: Inglês
10.1063/1.358965
ISSN1520-8850
AutoresTh. Mühge, Th. Zeidler, Q. Wang, Ch. Morawe, Naoto Metoki, H. Zabel,
Tópico(s)Physics of Superconductivity and Magnetism
ResumoThin epitaxial FexCo1−x alloy films sputtered on MgO(001) substrates were studied by x-ray scattering and by the magneto-optical Kerr effect in order to investigate the structural phase stability induced by the substrate and to relate the magnetic properties to the alloy film structure. Alloy films with a thickness of about 20 nm and concentrations from x=1 to x=0.3 exhibit a bcc (001) growth with the in-plane [100] axis parallel to the MgO[110] axis. For pure Co (x=0) a fcc (001) structure with the Co[100] axis parallel to the MgO[100] axis was obtained. For x=0.15 no out-of-plane or in-plane Bragg peak could be observed, possibly due to the bcc-fcc structural phase transition. Kerr rotation angles in saturation as a function of x reveal a shape similar to the Slater–Pauling curve. Magnetic hysteresis measurements reveal a fourfold anisotropy with easy axes parallel to the FexCo1−x[100] crystal axis for 1≥x≥0.8, and parallel to the FexCo1−x[110] crystal axis for 0.7≥x≥0.3. In pure Co the easy axis lies parallel to the fcc-Co[110] crystal axis. Finally, for x=0.28 a step in the magnetic hysteresis in the FexCo1−x[11̄0] direction indicates an overlap of a fourfold and twofold magnetic anisotropy.
Referência(s)