Influence of Na2TeO3 additive on electrodeposition of Zn–Mn alloy coatings from sulphate–citrate bath

The influence of Na2TeO3 additive in sulphate–citrate bath on electrodeposition of Zn–Mn alloy coatings was investigated by material characterisation methods and electrochemical techniques. The effects of small amounts (0·39–3·10 mM) of Na2TeO3 additive on cathode polarisation, composition and current efficiency were estimated. The crystal structure and surface morphology of Zn–Mn alloy coatings were studied by scanning electron microscopy (SEM) and powder X-ray diffraction spectroscopy (XRD) respectively. The SEM and XRD data showed that Na2TeO3 additive effectively accelerates phase transformation and reduces crystallite size.