Synthesis and characterisation of nanostructured Co–Pt magnetic films electrodeposited from tartrate-stabilised chloride baths

Abstract

Cobalt–platinum (Co–Pt) nanocrystalline alloy films were electrodeposited using a novel stable single-bath system containing a complex forming additive which stabilised the Co²⁺ ions and enhanced codeposition with platinum complexes. The compositions of the electrodeposits was controlled by adjusting the metal ions ratio in the electrolytic bath and by varying the current density. X-ray diffraction results showed that the as-deposited films contained face-centred cubic CoPt₃ phase and the calculated crystallite sizes were in nanoscale dimension in a range of 3–10 nm. Scanning electron microscopy results showed formation of granules and clusters. Atomic force microscopy and infinite focus microscopy results showed granular surface morphology and approximately similar surface roughness value on Co₄₃–Pt₅₇ film. Magnetic force microscopy characterisation on Co₄₃–Pt₅₇ showed existence of correlation between magnetic force and surface topography. The saturation magnetisation values of as-synthesised nanostructured Co–Pt films increased with increasing of Co content.

Keywords:

• Co–Pt
• Electrodeposition
• Magnetic films
• Magnetic force microscopy
• Nanocrystalline

Acknowledgements

This work was supported by the Institute of Research Management and Consultancy (IPPP) under grants PS125/2010B and HIR-MOHE Eng-12, University of Malaya.