Jahn-Teller structural phase transition around 280 K in LiMn{sub 2}O{sub 4}

Journal Article · Thu Jun 01 04:00:00 EDT 1995 · Materials Research Bulletin

DOI:https://doi.org/10.1016/0025-5408(95)00048-8· OSTI ID:82653

Yamada, Atsuo; Tanaka, Masahiro ^[1]

---

1. 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, Journal Name: Materials Research Bulletin Journal Issue: 6 Vol. 30; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL-PHASE TRANSFORMATIONS
CUBIC LATTICES
JAHN-TELLER EFFECT
LITHIUM OXIDES
MANGANESE OXIDES
SPINELS
TETRAGONAL LATTICES
THERMAL ANALYSIS
X-RAY DIFFRACTION