Electron Microscopic Investigations of Pyramidal Structures formed on the Surfaces of Electrodeposited Nickel

Abstract

IN a previous communication¹, we reported the development of various structures on the growing surfaces of electrodeposited nickel, using electron microscopy. The deposits examined were obtained by electrodepositing nickel, mainly on polycrystalline copper foils, at a current density of 10 m.amp/cm² from a Watt's type of bath at a temperature of 25°C. Deposition times of about 1 and 120 min were used for most of the work. The presence of growth features, such as sub-grain structures formed at an early stage and microcavities formed at an advanced stage of deposition, led us to believe that internal stresses associated with dislocations and other structural defects play an important part in the growth of cathodic crystals. Recently, we have observed by electron microscopy the development of pyramidal structures at intermediate times of deposition from the same baths and at the same deposition conditions as used previously. In this communication, results on the development of these structures are presented.