Influence of Bath Composition on Magnetic Properties of Electrodeposited Co-Pt-W Thin Films

• Published in: Journal of iron and steel research, international international, 2007-07, Vol.14 (4), p.65-68
• Main Authors: Ge, Hong-liang, Wei, Guo-ying, Wu, Qiong, Zhou, Qiao-ying, Wang, Xin-yan
• Format: Article
• Language: English
• Subjects: bath composition; Co-Pt-W thin film; electrodeposition; magnetic property; 电极沉淀; 电镀层; 磁铁性质; 金属学
• ISSN: 1006-706X; 2210-3988
• DOI: 10.1016/S1006-706X(07)60060-0

Effect of bath composition （[Co^2＋]/[-Pt^Ⅳ ] and [-WO4^2- ], [cit^-]） and pH on the magnetic properties of electrodeposited Co-Pt-W thin films has been investigated. Electrodeposited Co-Pt-W thin films exhibited strong perpendicular magnetic anisotropy when the ratio of [-Co^2＋ ] to [-Pt^Ⅳ ] was 10 ; cathode current efficiency and perpendicular magnetic anisotropy showed little variations when [WO4^2- ] was lower than 0. 1 mol/L, but perpendicular magnetic anisotropy had strengthened when [WO4^2-] was over 0. 1 mol/L, which could be explained by the fact that the hydrogen evolution could produce pores as magnetic domain pinnings; citrate as complexing reagent can promote the polarization of [Co^2＋] and [Pt^Ⅳ]. As a result, the equilibrium electrode potentials of cobalt and platinum moved to negative direction, which led to the co-deposition of Co, Pt, and W. It was also found out that the as-deposited Co- Pt-W hard magnetic thin films were very homogeneous, smooth, and had the maximum coercivity for the bath pH 8. 5 and the concentration of citrate 0. 26 mol/L.