Heat capacity and thermodynamic functions of zirconia and yttria-stabilized zirconia

✍ Scribed by Takeo Tojo; Tooru Atake; Toshiyuki Mori; Hiroshi Yamamura

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 705 KB
• Volume: 31
• Category: Article
• ISSN: 0021-9614
• DOI: 10.1006/jcht.1998.0481

✦ Synopsis

Heat capacities of pure zirconia ZrO 2 and 7.76•10 -2 mole fraction yttria-stabilized zirconia (ZrO 2 ) 0.9224 (Y 2 O 3 ) 7.76•10 -2 were measured by adiabatic calorimetry at temperatures between 13 K and 300 K. The results were compared and analysed from the standpoint of the effects of yttria doping. The yttria-stabilized zirconia showed excess heat capacity at low temperatures which should be attributed to so-called low-energy modes caused by the defects in the crystal. The smoothed values of molar heat capacities at rounded temperatures were calculated from the experimental data. The thermodynamic functions enthalpy, entropy, and Gibbs free energy were also calculated and tabulated. The standard enthalpy and entropy of pure zirconia and 7.76•10 -2 mole fraction yttria-stabilized zirconia at