Structure, composition, and superconductive properties of superthin niobium films condensed under autoion bombardment conditions

The goal of the present study is to determine the main impurity source in films produced by ion seeding and to determine the possibility of producing superthin superconductive niobium layers under ''industrial'' vacuum conditions by this method. The deposition method and film study are reviewed in depth, and the elemental composition of the condensates was determined by electron Auger spectroscopy with layer-by-layer ionic etching. The technique of condensing Nb films with autoion bombardment under industrial vacuum conditions permits production of superthin Nb layers with maximum temperature of transition to the superconductive state and high electrical resistance ratio.