Neutron Scattering Measurements Of Magnetic Excitations In Gd/Y Superlattices

Neutron inelastic scattering has been used to measure the magnetic excitations as a function of applied magnetic field in an antiferromagnetically coupled Gd/Y superlattice. The excitations were measured along the c-axis, which is parallel to the normal of the interfaces and the sample growth direction. Dispersive spin waves were unambiguously detected on the application of a magnetic field. The spin waves are shown to renormalize with field following a basic model drawn from standard spin wave theory. The model required no free parameters aside from an initial amplitude. (C) 2010 American Institute of Physics. [doi:10.1063/1.3428425]