Jahn-Teller structural phase transition around 280 K in LiMn{sub 2}O{sub 4}
- Sony Corp. Research Center, Yokohama (Japan)
The structural phase transition of spinel LiMn{sub 2}O{sub 4} (Fd3m at room temperature) was investigated using thermal analysis and powder x-ray diffraction. The phase transition was observed around T{sub t} = 280 K with a temperature hysteresis of about 10 K. It was revealed that the low temperature phase (T < T{sub t}) is a mixture of Fd3m (c/a = 1) and I4{sub 1}/amd (c/a = 1.011). The phase transformation from Fd3m to I4{sub 1}/amd proceeds with the decrease in temperature until the volume fraction of the I4{sub 1}/amd phase saturates at 65% at around 260 K, just below T{sub t}. The single phase of I4{sub 1}/amd never appeared even at 220 K, far below T{sub t}. This phase transition is of a first-order character and is owing to the cooperative Jahn-Teller effect of Mn{sup 3+}. Cell performance utilizing the LiMn{sub 2}O{sub 4} cathode is also discussed.
- OSTI ID:
- 82653
- Journal Information:
- Materials Research Bulletin, Vol. 30, Issue 6; Other Information: PBD: Jun 1995
- Country of Publication:
- United States
- Language:
- English
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