硫酸钴浓度对电沉积Co-W-P薄膜结构与磁性能的影响

Effect of cobalt sulfate concentration on structure and magnetic performance of Co-W-P thin film

在20#钢基体上电沉积Co-W-P薄膜,并研究镀液中硫酸钴浓度对Co-W-P薄膜的结合强度、结构、成分、厚度和磁性能的影响。结果表明:Co-W-P薄膜与20#钢基体结合紧密,随着硫酸钴浓度从5 g/L增至25 g/L,Co-W-P薄膜的结构和物相无明显变化,但平均晶粒尺寸呈现先减小后增大的趋势,Co元素的质量分数呈现先升高后降低的趋势,导致不同Co-W-P薄膜的致密性和磁性能存在差异。当硫酸钴浓度为15 g/L时,Co-W-P薄膜的平均晶粒尺寸仅为40.6 nm,Co元素的质量分数达到64.19%,具有最大的矫顽力(932 A/m)和饱和磁化强度(100.7 A·m2·kg-1),其结构致密并且展现出良好的磁性能。在一定范围内硫酸钴浓度的增加,降低了成核过电位,使晶粒细化且结合紧密,同时提高了钴还原沉积效率,使Co元素的质量分数升高。研究表明:晶粒细化、致密性改善以及磁性元素的协同作用进一步提高了Co-W-P薄膜的磁性能。

Co-W-P thin film was electrodeposited on 20#steel substrate,and the effect of cobalt sulfate concentration in the plating solution on the bonding strength,structure,composition,thickness and magnetic performance of Co-W-P thin film was investigated.The results showed that Co-W-P thin film was closely combined with the 20#steel substrate.With the increase of cobalt sulfate concentration from 5 g/L to 25 g/L,the structure and phase of Co-W-P thin film did not change significantly,but the average grain size decreased first and then increased,and the mass fraction of Co element increased first and then decreased,resulting in differences in the compactness and magnetic performance of different Co-W-P thin films.When the cobalt sulfate concentration was 15 g/L,the average grain size of the Co-W-P film was only 40.6 nm,of which the mass fraction of Co element reached 64.19%,and the maximum coercivity and saturation magnetization were 932 A/m and 100.7 A∙m2∙kg-1 respectively,indicating that the Co-W-P thin film had a dense structure and exhibited good magnetic performance.With the increase of cobalt sulfate concentration in a certain range,the nucleation overpotential was reduced,and the grains were refined and tightly bonded.Meanwhile,the reduction deposition efficiency of cobalt was increased,and the mass fraction of Co element was also increased.The results showed that the magnetic properties of Co-W-P thin films were further improved by grain refinement,compactness improvement and the synergistic effect of magnetic elements.