Ag–W electrodeposits with high W content from thiourea–citrate electrolytes

Abstract

Abstract Thin film deposits containing silver and tungsten were electrodeposited onto rotating cylinder electrodes from non-cyanide, acidic thiourea–citrate electrolytes. The effect of current density and tungsten ion electrolyte concentration on the deposit composition and partial current densities was examined. Deposit composition was measured using X-ray fluorescence with increasing amount of tungsten ion in the electrolyte at high current densities, with silver ion reduction under mass transport control and the tungsten ion reduction under a kinetic control. The highest wt.% W in the deposit was 18 wt.%, SEM-EDS was also used to characterize the deposit morphology and account for sulfur in the deposit, originating from the thiourea in the electrolyte.