Abstract

Co–Ni thin films alloys were deposited on ruthenium substrates by the electrochemical method from chloride bath at pH 3.8. The effect of cobalt content on the composition, morphology, electrochemical and microstructural properties of the electrodeposited thin films was investigated. Effectively, the conditions of electrodeposition of Ni–Co deposits were determined using the cyclic voltammetry at three ions concentration ratios Co/Ni (5:1, 1:1 and 1:5). Combined results from the potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) study, show an excellent corrosion resistance for the deposits obtained when the cobalt concentration is low. The morphology of the electrodeposited Co–Ni alloys thin films is intimately associated with the Co content in the bath. Atomic force microscopy (AFM) observations of the deposits show a granular structure of the electrodeposited thin films and when the amount of Co was decreased in the solution bath; a strong decrease in the grain size was observed. X-ray diffraction measurements (XRD) indicate a small crystallite size with the presence of a mixture of hexagonal close-packed (hcp) and face-centered cubic (fcc) Co–Ni structures. The phase structure gradually changed from fcc to hcp with the increase of cobalt content.

摘要

Co-Ni 薄膜合金通过电化学方法从 pH 3.8 的氯化物浴中沉积在钌基体上。研究了钴含量对电沉积薄膜的组成、形貌、电化学和微观结构性能的影响。有效地，使用循环伏安法在三种离子浓度比 Co/Ni（5:1、1:1 和 1:5）下确定 Ni-Co 沉积物的电沉积条件。动电位极化和电化学阻抗谱 (EIS) 研究的综合结果表明，钴浓度低时获得的沉积物具有出色的耐腐蚀性。电沉积 Co-Ni 合金薄膜的形态与镀液中的 Co 含量密切相关。沉积物的原子力显微镜 (AFM) 观察显示电沉积薄膜的颗粒结构，当溶液浴中 Co 的量减少时；观察到晶粒尺寸的强烈减小。X 射线衍射测量 (XRD) 表明存在小晶粒尺寸，存在六方密堆积 (hcp) 和面心立方 (fcc) Co-Ni 结构的混合物。随着钴含量的增加，相结构逐渐从fcc变为hcp。