In-Situ Ferromagnetic Resonance \2013 Polarised Neutron Reflectivity

Here, we aim to test a new beam capability: in-situ ferromagnetic resonance (FMR) with polarised neutron reflectivity (PNR). When placed in an external magnetic field, the magnetisation of a ferromagnetic material will precess about the external field in what is known as Larmor precession. If an alternating RF field is applied perpendicular to the external field at the Larmor precession frequency, there is a maximum in the absorbance and the cone angle of precession increases. Understanding magnetisation dynamics and FMR is key to many spintronics and magnonics applications as it determines e.g. the speed and energy cost of switching the magnetisation. FMR is also used in the transmission of angular momentum to non-magnetic layers for the generation and propagation of dissipationless spin currents and in the spin ↔ voltage conversion via the (inverse) spin Hall effect.