Observation of magnons by light scattering in epitaxial CoFe/Mn/CoFe trilayers

Abstract

We report on Brillouin scattering measurements on a CoFe/Mn/CoFe trilayer film characterized by unusually large biquadratic coupling. The magnetic field dependence of the exchange coupled in- and out-of-phase magnons as well as their in-plane directional dependence are determined. The saturation magnetization of the trilayer was measured independently through superconducting quantum interference device magnetometry. The spin wave data is well represented by a generalization of the model that takes into account the antiferromagnetic order in the Mn layer.

Brillouin light scattering of CoFe/IrMn-based top and bottom spin-valves

“…It is also noticed that both values for k s are positive. These suggest that the interfacial anisotropy energy always tends to align the magnetization out of the film plane, i.e., along the (1 1 1) crystallographic axis, supporting the conclusions for CoFe/Mn/CoFe-trilayers, investigated by the same method [16]. However, a detailed comparison cannot be made, since the surface anisotropy depends on various growth conditions and different kinds of antiferromagnetic materials, as well as the thickness of antiferromagnetic layer.…”