Effect of Nd-Doping on the Microstructure and Magnetic Properties of Nd_X(Fe_47.5Pd_52.5)_100-X Films

In order to investigate the effect of rare earth Nd doping on FePd alloy thin films, the samples of Nd_x(Fe_47.5Pd_52.5)_100-x (x = 0, 2, 2.7, 3.4, 4) films were prepared by a DC magnetic sputtering method. The microstructure and magnetic properties were characterized by XRD, EDS, PPMS et al. The XRD data indicated that the addition of rare earth element Nd could significantly shorten the annealing time and the annealing temperature from the disordered FCC phase to the ordered FCT phase and increase the driving force of the phase transition. In addition, the appropriate addition of Nd element also has the role of grain refinement. The grain size could reach 29–14 nm and the appropriate grain size was conducive to the exchange coupling between the grains. The hysteresis loop of the films showed that the coercivity (Hc) and remanence ratio (Mr/Ms) first increased with the increase of Nd content sharply and then decreased. When the content of rare earth x = 2.7, the maximum coercivity was 3.05 kOe. The changes of coercivity and remanence ratio with the increase of annealing temperature also first increased and then decreased, and reached the maximum at 550 °C.