Preparation and Character of Co-Gd Films Electroplated in Urea-Acetamide-NaBr Melt

Abstract

Abstract The Co-Gd film was prepared in urea-acetamide-NaBr melt at 393 K by an electrodeposition method. The cyclic voltammetry was used to investigate the co-deposition behavior of Gd and Co. Using the techniques, such as scanning electron microscope (SEM), energy-dispersive X-ray spectral analysis (EDS) and X-ray diffraction (XRD), the effects of the cathodic current density on the composition, the surface morphology and the structure of the coating were studied. Results show that the content of Gd in the coating increases at first and decreases later with the increasing current density, and reaches the maximum value of 54.97% (mass fraction, similarly hereinafter) at 12.5 mA/cm2. The surface morphology of the deposit becomes rough with the increase of the content of Gd in the coating. The as-plated deposit consists of amorphous phase, and the deposit is converted into cobalt (Fm3m) phase at 300 °C, and transformed into GdCo5 (P6/mmm) at 600 °C. The magnetic properties of the coating were measured by vibrating sample magnetometer(VSM). The experimental results reveal that the Gd content has great influence on magnetic properties of the alloy films. During heat treatment, the film saturation magnetization come to the maximum value of 550.43 kA/m at 600 °C, and the film coercive force reaches the maximum of 34.97 kA/m at 400 °C.