The electrochemical co-deposition of iron and gallium from a simple aqueous electrolyte was investigated by means of the electrochemical quartz crystal microbalance technique. The results reveal that alloy deposition occurs at potentials more positive than the deposition potential of single gallium. At the same time, large amounts of hydroxides are chemically precipitated due to a pH increase caused by strong hydrogen evolution. If the pH increase is compensated by applying potential pulses, these hydroxides are re-dissolved and metallic alloy films with low oxygen content are directly accessible. XPS and TEM investigations confirm the formation of an Fe100-xGax alloy (x = 20 +/- 4 at.%). (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.028207jes] All rights reserved.