Magnetic characteristics and core loss separation in magnetostrictive FeGa and FeGaRE (RE = Tb, Y) alloys

Magnetic characteristics of magnetostrictive materials at elevated frequencies largely determine the performance and energy efficiency of devices based on them. The paper presents the wide frequency and magnetic field range dependences of core losses and permeability in classical binary alloy Fe81Ga19. For a more detailed analysis, we carried out the separation of energy losses according to two theories (Bertotti and Landgraf). The movability of domain walls and the proportions of magnetization processes resulting from Bertotti's and Landgraf's theories were analyzed on FeGa alloy. The same set of studies was carried out for rare-earth (RE) doped alloys, which are considered a promising replacement for a binary alloy. In particular, low-RE (Fe81Ga19)99.8Tb0.2 and high-RE (Fe81Ga19)97Y3 alloys were used. The RE effect on the magnetic properties of FeGa alloy was studied for the first time. In all samples, the structure and basic properties were examined to establish their correlation with the behavior of a material at elevated frequencies. •Core losses separated in monolithic Galfenol applying Bertotti and Landgraf theories.•Effect of RE doping on wide frequency and magnetic field range magnetic properties.•Relatively high initial permeability with good stability at application frequencies.•RE doping increased coercivity, but decreased excess losses hence AC loss component.