Abstract

Raman spectroscopic studies on pulsed laser deposited nanostructured LiCoO2 thin film cathodes

Author(s): M.C.Rao

Thin films of LiCoO2 were prepared by pulsed laser deposition technique. Two important deposition parameters such as substrate temperature and oxygen partial pressure during the thin film deposition were controlled. The Raman data consist of a series of broad bands located between 400 and 700cm-1 for LiCoO2 films. The Raman band located at 592cm-1 can be viewed as the symmetric Co-O stretching vibration of CoO6 groups. This band is assigned to the A1g symmetry. The RS peak position at 484cm-1 derives fromthe Eg species. The symmetric motions involve Co-O stretching and O-Co-O bending vibrations. The intensity ratio increased with the increase of substrate temperature. The filmdeposited at 700ï‚°C in pO2=100 mTorr, indicating that the filmhad no preferred orientation.