Structural Evolution and Stability of RF Sputter Deposited Li xMn2-yO4 Thin Film Cathodes
Journal
Journal of the Electrochemical Society
Journal Volume
151
Journal Issue
3
Pages
A452-A455
Date Issued
2004
Author(s)
Abstract
Thin films of compounds were deposited by radio frequency (rf) magnetron sputtering from a sintered target on Si substrate under working pressures of 0.4 Pa and 2 Pa (pure Ar gas). In situ substrate heating was applied to modify the film crystallography. The films deposited at a pressure of 2 Pa with substrate heating developed a (111) texture with increase of substrate temperature. To compare the structural stability of deposited films, rapid thermal anneal (RTA) of was performed. Films deposited under different conditions exhibited different trends of structural evolution, as treated by RTA. The crystal structure evolution of films deposited under different conditions was studied by X-ray diffraction and micro-Raman spectroscopy. The films deposited at elevated temperature retained the cubic spinel structure after RTA treatment of 700°C, while the films deposited without substrate heating showed significant cationic disorder after RTA. The discharge curves of the half-cells made of thin films were measured. It was demonstrated that the films deposited with in situ substrate heating exhibited larger capacity compared with other films. The more stable spinel phase on the films deposited with in situ heating may be responsible for the enhanced capacity. © 2004 The Electrochemical Society. All rights reserved.
Type
journal article