Structural Evolution and Electrochemical Performance of Sputter-Deposited Cu[sub 6]Sn[sub 5] Thin-Film Anodes

thin-film anodes have been prepared by magnetron cosputtering, and the electrochemical properties of the deposited films in relation to lithium have been investigated. Structural evolution of the thin films was induced by in situ substrate bias, which then resulted in different electrochemical properties. The crystallinity of the deposited thin films can be well controlled under precise substrate bias. Films deposited with substrate bias ranging from showed nearly amorphous structure, with nanosized particles on the surface. These films exhibited typical electrochemical properties of nanocrystalline . As the substrate bias became more intense, polycrystalline films formed. At a bias of , highly crystallized films were obtained. The postcycled X-ray diffraction spectra indicated a phase in the film made with bias. This phase was associated with the intercalation process normally found in the high-temperature-phase . The results show that in situ bias is able to induce phase transformation of without thermal annealing. The nonbias-deposited films showed electrochemical characteristics of the low-temperature phase, whereas the bias-deposited films showed properties of the high-temperature phase.