Structure of Heteroepitaxial Nickel Electrodeposits on the Iron Substrate

With special attention to the fine structure of electrodeposits and the deposit/substrate interface, the heteroepitaxial growth of nickel electrodeposits on a polycrystalline iron substrate has been studied mainly by transmission electron microscopy. The nickel deposits grow heteroepitaxially even at such a high current density as 500 A/m₂ on a chemically cleaned substrate iron. The crystallographic orientation relationship between the nickel deposits and the iron substrate is that of Kurdjumov-Sachs, i.e. (110)_α⁄⁄(111)_Ni, [111]_α⁄⁄[110]_Ni. The nickel heteroepitaxial deposits consist of columnar crystals which contain dense dislocations at the interface. There dislocations are introduced in order to reduce the misfit strain at the interface.