Additive-assisted cobalt electrodeposition as surface magnetic coating to enhance the inductance of spiral copper inductors

Abstract

In this work, the electrochemical experiments and quantum chemical calculations are performed to investigate the possible mechanism of glycine (Gly) and 3-mercapto-1-propane sulfonate (MPS) during cobalt electrodeposition. It is found that the adsorption behavior of Gly on the electrode surface suppresses the electrodeposition of cobalt, whereas the capture of cobalt cations by sulfonic end groups facilitates the electron transfer and contributes to the acceleration of cobalt electrodeposition with the addition of MPS. Moreover, the crystal structure, surface morphology and magnetic performance of cobalt deposits are characterized to investigate the effects of Gly and MPS. Scanning electron micrographs indicate that the suppression of Gly and the acceleration of MPS on the growth of cobalt particles cause the different surface morphologies. X-ray diffraction and electron backscatter diffraction results indicate that the growth of (10¯10), (10¯11) and (11¯20) crystal planes is inhibited in the presence of MPS. Moreover, the synergistic effect of Gly and MPS is advantageous for obtaining the cobalt deposit with desirable magnetic performance. The inductance of copper inductors with cobalt deposits as the surface magnetic coating is improved by 11%.