Calorimetric Study of the La2Hf2O7 Heat Capacity in the Range 57–302 K
| Autor: | S. M. Lakiza, Ya. S. Tishchenko, A. R. Kopan, M. P. Gorbachuk |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Materials science
Enthalpy Metals and Alloys chemistry.chemical_element 02 engineering and technology Calorimetry 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Heat capacity 0104 chemical sciences Gibbs free energy symbols.namesake chemistry Mechanics of Materials Materials Chemistry Ceramics and Composites Thermodynamic free energy Lanthanum symbols Physical chemistry Isostructural 0210 nano-technology Adiabatic process |
| Zdroj: | Powder Metallurgy and Metal Ceramics. 54:696-703 |
| ISSN: | 1573-9066 1068-1302 |
| Popis: | The heat capacity of La2Hf2O7 has been studied in the range 57–302 K by adiabatic calorimetry. The heat capacity C p of lanthanum hafnate changes monotonically and there are no anomalies. The values of heat capacity, entropy, enthalpy, and reduced Gibbs energy have been determined in standard conditions: C ° (298.15 K) = 229.39 ± 0.92 J · mol–1 · K–1, S° (298.15 K) = 246.9 ± 2 J × × mol–1 ∙ K–1, Ф° (298.15 K) = 114.76 ± 1.72 J ∙ mol–1 ∙ K–1, and H° (298.15 K)–H° (0 K) = 39403 ± 197 J ∙ mol–1. In the series of isostructural La2Zr2O7 → La2Hf2O7 compounds, atomic oscillation frequency in the lattice decreases and low-temperature heat capacity increases with greater mass of oscillator atoms from Zr to Hf. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink