Title :
Effect of an Au underlayer on perpendicular magnetic anisotropy in Au/Co/Au(111) sandwich films
Author :
Murayama, Akihiro ; Hyomi, Kyoko ; Eickmann, James ; Falco, Charles M.
Author_Institution :
Dept. of Phys., Arizona Univ., Tucson, AZ, USA
fDate :
7/1/1998 12:00:00 AM
Abstract :
We have used spin-wave Brillouin scattering to study perpendicular magnetic anisotropy in Au/Co/Au(111) sandwiched films with varying thicknesses of Au-underlayers. By using 5-monolayer (ML)-thick Co films, the transition of spin-wave frequency between out-of-plane and in-plane magnetizations can be observed by varying the in-plane field. We find that the field-dependence of the spin-wave energy is explained by a calculation including both the first-order (second power) and the second-order uniaxial perpendicular anisotropies depending on the Au-underlayer. We observe saturation of the anisotropy at 5 ML of Au-underlayer thickness, which corresponds to the saturation of in-plane lattice expansion of Co on that Au-underlayer. The contribution of interface anisotropy is evaluated from the Co-thickness dependence of the anisotropy observed. We also have observed a field-dependent broadening of the spin-wave Brillouin spectra at a critical field between out-of-plane and in-plane magnetizations, which we attribute to a distribution of the first-order anisotropy
Keywords :
Brillouin spectra; cobalt; ferromagnetic materials; gold; magnetic thin films; magnetisation; perpendicular magnetic anisotropy; spin waves; Au underlayer; Au-Co; Au/Co/Au(111) sandwich films; field-dependence; in-plane lattice expansion; in-plane magnetizations; interface anisotropy; out-of-plane magnetizations; perpendicular magnetic anisotropy; spin-wave Brillouin scattering; spin-wave energy; spin-wave frequency; Anisotropic magnetoresistance; Brillouin scattering; Frequency; Gold; Magnetic anisotropy; Magnetic films; Magnetic hysteresis; Perpendicular magnetic anisotropy; Perpendicular magnetic recording; Saturation magnetization;
Journal_Title :
Magnetics, IEEE Transactions on