Improvement of magnetic properties of electrodeposited CoNiMnP–BaFe12O19 nanocomposite coatings in presence of sodium lauryl sulphate

Abstract

Electrodeposition is an attractive method for preparing electromagnetic micro-electromechanical system actuators, and composite electrodeposits incorporating ferromagnetic particles exhibit excellent magnetic properties. Thus, an increasing research effort has been made to optimising the electrodeposition of magnetic composite coatings. In the present paper, sodium lauryl sulphate has been introduced to improve the weight per cent of ferromagnetic particles embedded in CoNiMnP–BaFe12O19 composite coatings, and careful investigation of the effect of varying sodium lauryl sulphate concentration on the surface morphology, element weight fraction and magnetic properties of composite coatings, is carried out. The results demonstrate that the addition of sodium lauryl sulphate in the concentration range from 0·8 to 4 g L−1 favours the inclusion of magnetic particles into the alloy deposit; the maximum weight per cent of BaFe12O19 particles in the nanocomposite coatings, 18·28 wt-%, is acquired with the addition of 4 g L−1 sodium lauryl sulphate. However, it should be noted that the CoNiMnP–BaFe12O19 composite coatings with the highest BaFe12O19 weight fraction did not exhibit the highest coercivity and maximum energy density in the present experiment. The CoNiMnP–BaFe12O19 nanocomposite coatings with a high coercivity of 1438 Oe, a high retentivity of 0·39 T, and maximum magnetic energy density of 15·41 kJ m−3 have been obtained at a sodium lauryl sulphate concentration of 3 g L−1.