Ferromagnetic resonance study of equiatomic FeRh thin films

Chemically ordered FeRh alloy with nearly equiatomic composition is antiferromagnetic at room temperature and exhibits a first-order phase transition to the ferromagnetic (FM) state at 370 K. Here, we present the study of FM resonance (FMR) in non-capped and Pt-capped magnetron sputtered 40 nm FeRh films on a MgO(100) substrate and analyse the influence of ion irradiation and chemical disordering on their magnetic properties. The temperature dependent FMR study between 200-500 K allowed us to observe the hysteretic temperature behavior, accompanied by a clear transformation of the FMR line, and explore the complex magnetic structure of films. We distinguished and characterized the contribution of anomalous FM interfacial layers induced by atomic intermixing and lattice strain. Finally, we have revealed the formation of a magnetic phase with an out-of-plane easy axis of magnetization caused by low-fluence irradiation with Ne+ ions.