电沉积条件对钴-锰合金结构和磁性能的影响

以柠檬酸为络合剂和硼酸为缓冲剂的酸性硫酸盐镀液中电沉积Co-Mn合金，循环伏安实验显示Co-Mn的起始共沉积电位约-1.282 V(vs.Hg-Hg2SO4 , sat.K2SO4)。借助扫描电镜(SEM)、能谱分析(EDS) 、X射线衍射(XRD)和振动样品磁强计(VSM) 研究了沉积条件对镀层结构和磁性能的影响。结果表明，Co-Mn镀层的组成受沉积条件影响较大；在镀液pH 4.0时，随着阴极电流密度从10 mA•cm-2增加到40 mA•cm-2，镀层中锰含量从0.3 at%增大到6.6 at%；镀层结构由hcp的固溶体转为fcc的固溶体；随着镀层中锰含量增加，膜的饱和磁化强度开始增大，然后降低，最大饱和磁化强度为1926.0 kA•m-1，膜的矫顽力在31.6 ~ 33.9 kA•m-1范围。

Influence of the Electroplating Conditions on the Structure and Magnetic Performances of the Co-Mn Alloy

The Co-Mn alloys were electro-plated from the acid sulfate salt plating solution containing sodium citrate as complexing agent and boric acid as a buffer agent. The cyclic voltammetric experiments showed that the initiative co-deposition potential of the alloy is about -1.282 V (vs. Hg-Hg2SO4 , sat.K2SO4). The effect of the plating conditions on the structure and the magnetic performances of the Co-Mn coating were studied by scanning electron microscope (SEM), energy dispersive X-ray spectrum (EDS), X-ray diffractometry (XRD) and vibrating sample magnetometer (VSM), respectively. As a result, the influence of the plating conditions on the coating’s composition is relatively remarkable. With the increase of the cathodic current density from 10 to 40 mA•cm-2 at the plating bath pH 4.0, the manganese content of the coating increases from 0.3 at% to 6.6 at%, and The coating structure is transform from hcp Co-Mn solid solution into fcc Co-Mn solid solution. With the increase of the manganese content of the film, the saturation magnetization increases, then, it decreases. The maximal saturation magnetization reaches 19262.0 kA•m-1. The value of the film coercive force ranges from 31.6 kA•m-1 to 33.9 kA•m-1.