Co-Gd合金在尿素-乙酰胺-NaBr熔体中的电沉积及合金性能(英文)

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

在尿素-乙酰胺-NaBr熔盐中采用电沉积方法制备了Co-Gd合金薄膜。运用循环伏安技术研究了Gd、Co的共沉积行为。通过扫描电子显微镜、X射线能谱仪和X射线衍射仪研究了电流密度对镀层表面形貌、元素组成及镀层结构的影响。研究发现,Gd含量随着电流密度的增加呈先增加后减少的趋势,在电流密度为12.5mA/cm2时达到最大含量54.97%(质量分数)。镀层的表面形貌随着Gd含量的增加而变得粗糙。镀态时镀层结构为非晶态,300°C热处理后转化为Co(Fm3m)相,在600°C热处理后又出现GdCo5(P6/mmm)相。采用振动样品磁强计测试了镀层的磁性能。结果表明,镀层中Gd的含量对镀层的磁性能有重要影响。在热处理过程中,镀层的饱和强度在600℃热处理时达到最大值550.43kA/m,而矫顽力则在400℃热处理时达到最大值34.97kA/m。

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℃, and transformed into GdCo5 （P6/mmm） at 600℃. 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 ℃, and the film coercive force reaches the maximum of 34.97 kA/m at 400 ℃.