Abstract
The enthalpies of transition among the Tx, T′, and T-La2CuO4 phases are obtained from a combination of differential scanning calorimetry, high temperature oxide melt solution calorimetry, and transposed temperature drop calorimetry. The enthalpy of transformation of Tx to T is 2.32 ± 0.07 kJ/mol and the corresponding entropy of transition is 4.38 ± 0.13 J/(mol K). The T′ modification, with an average of 1.40 kJ/mol, is less stable in enthalpy than Tx but at 0.96 kJ/mol, more stable in enthalpy than T. Although we cannot rule out a small stability field at temperatures near the Tx-T transition at 530 K, T′ is most likely metastable at all temperatures.
Original language | English (US) |
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Pages (from-to) | 91-94 |
Number of pages | 4 |
Journal | Journal of Solid State Chemistry |
Volume | 204 |
DOIs | |
State | Published - 2013 |
Externally published | Yes |
Keywords
- High-temperature calorimetry
- High-temperature superconductor
- Thermodynamics
- Transition enthalpies
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry