Application of joint electric arc evaporation and magnetron sputtering to obtain thin films of Nb3Sn

Abstract

The study is aimed to the production of thin films of triniobium strannide (Nb3Sn) on sapphiresubstrates by layer-by-layer deposition using an arc evaporator with a niobium cathodeand a magnetron sputtering system with a tin target. To obtain the superconducting phase, hightemperatureannealing of the films was carried out in a vacuum furnace at a temperature of 800 °Cfor 1 hour. The elemental composition was studied using a scanning electron microscope with anattachment for energy-dispersive X-ray spectroscopy. An X-ray diffractometer was used to studythe phase composition. Before deposition, the samples were cleaned with argon ions using an ionsource. The elemental composition of the coatings was regulated by changing the power supplied tothe magnetron, the operating parameters of the arc evaporator were unchanged. The film depositedat a magnetron power of 200 W meets the requirements for tin concentration. A slight increase inpower leads to a sharp increase in the tin concentration. Annealing leads to the formation of therequired Nb3Sn intermetallic compound, and the presence of a harmful Nb6Sn5 compound was alsodetected. The diffraction pattern of the coating with an increased Sn concentration after annealing ischaracterized by a large number of intense Nb6Sn5 peaks and several Nb3Sn peaks.