Structural analysis of submicrometer LiCoO2 films

Submicrometer LiCoO2 films were prepared with pulsed laser deposition (PLD) and rf sputtering using stoichiometric targets. The influences of both sub strate material and annealing procedure on the polycrystalline microstructu re of the LiCoO2 films were investigated. XRD analysis revealed strong pref erential orientation: annealed films deposited with PLD had their (00l) pla nes parallel to the surface, while rf sputtered films had their (110) plane s in this orientation. The rf-film also developed the (003) reflection typi cal of PLD-films, but only after prolonged annealing at 600 degreesC. The d egree of preferential orientation is influenced significantly by the anneal ing procedure and only little by the substrate material and the thickness o f the deposited him. Pulsed laser deposition on an rf-sputtered seed layer revealed the PLD-film reflections. Extinction of the otherwise dominating ( 003) reflection indicated a random cationic distribution in LiCoO2, with an NaCl-type structure. (C) 2001 The Electrochemical Society. All rights rese rved.