Jahn-Teller instability in spinel Li-Mn-O
Abstract
Various compositions in the spinel Li-Mn-O system were prepared and characterized by thermal analysis, X-ray diffraction, and X-ray absorption spectroscopy, with special attention to the Jahn-Teller (JT) instability of Mn 3+. Of particular interest are (1) the discovery of JT structural phase transitions around 280 K, demonstrating that LiMn 2O 4 involves large JT instability in spite of its cubic symmetry at room temperature, (2) the use of transition temperature, Tt, and latent heat, Δ H, as sensitive parameters of JT instability in the practical composition region of the spinel Li-Mn-O ternary system as a 4 V cathode, and (3) the identification of the large, non-cooperative local JT distortion around Mn 3+ in the cubic phase.
- Publication:
-
Journal of Power Sources
- Pub Date:
- 1999
- DOI:
- 10.1016/S0378-7753(99)00106-8
- Bibcode:
- 1999JPS....81...73Y