Influence of deposition parameters on the electrodeposited ternary CoFeCu coatings

The CoFeCu coating was electrodeposited onto a silicon substrate from a sulfate solution containing organic additives (saccharin and sodium acetate). The effects of deposition time and metal ion concentration in the bath on the magnetic and microstructural properties were studied. The deposited films were characterized by scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), atomic force microscopy (AFM), and vibrating sample magnetometer (VSM) measurements. Composition analysis revealed that different ternary Co₇₂Fe₁₅Cu₁₃, Co₈₁Fe₁₀Cu₉, and Co₇₇Fe₁₈Cu₅ samples were obtained when the deposition times were varied. The SEM images of the CoFeCu samples exhibited a compact surface comprising finer grain agglomerates. The Co₇₇Fe₁₈Cu₅ samples plated at longer deposition times showed the formation of nano-voids compared to the Co₇₂Fe₁₅Cu₁₃ and Co₈₁Fe₁₀Cu₉ samples plated at shorter deposition times. In all samples, the fcc(Co) phase was dominant. From the magnetic analysis, good soft magnetic properties were obtained, with a coercivity of 6 Oe and a saturation magnetization of 1494 emu/cm³ (1.87 T) for the Co81Fe10Cu9 sample. Increasing the concentration of cobalt ions and decreasing the concentrations of iron and copper ions in the electroplating solution improved the soft magnetic properties of the CoFeCu deposit. The composition of the CoFeCu deposit changed as the concentration of cobalt ions was increased in the electroplating solution. The Co₈₁Fe₁₀Cu₉ sample had a higher saturation magnetization (MS) of 2005 emu/cm³ (2.5 T) and an acceptable lower coercivity of 19 Oe. This work successfully fabricated CoFeCu thin films with good soft magnetic properties on a Si substrate.