Periodic reverse current electrodeposition of gold in an ultrasonic field using ion-track membranes as templates: growth of gold single-crystals

Reversal of current electrodeposition has been applied to grow gold single- crystals in organic ion-track membranes used as templates. The influence of an ultrasonic agitation of the electrolyte has been also investigated. Two electrolytes were used for gold deposition: (1) potassium dicyanoaurate(I) and (2) sodium disulfitoaurate(I) solutions. Gold single-crystals have bee n successfully grown only from the cyanidic solutions. The perfection of th e crystals was defined by the deposition conditions, namely by the paramete rs of the reverse current pulses. The ultrasonic field led to a depolarizat ion effect that favoured the growth of single-crystals when a direct curren t was used. Its influence on the crystal growth during pulse electrolysis w as not so pronounced. However, the macrothrowing power of the bath was incr eased. Gold deposition from a sodium disulfite bath resulted in polycrystal line claddings independent of the variation of deposition conditions. (C) 2 000 Elsevier Science Ltd. All rights reserved.