Heat Capacities at Low Temperatures of Titanium Dioxide (Rutile and Anatase)¹

Thermodynamic properties of illite, smectite and beidellite by calorimetric methods: Enthalpies of formation, heat capacities, entropies and Gibbs free energies of formation

“…Heat capacity data for quartz between 50 and 520 K were provided by Richet et al (1982). For kaolinite, data were taken from Robie and Hemingway (1991) between 5 and 298 K and from Robie and Hemingway (1995) above 298 K. Heat capacity data for anatase were given by Shomate (1947), from 50 to 298 K and Robie and Hemingway (1995) above 298 K. The heat capacity data for the dehydrated beidellite are listed at selected temperatures in Table 7.…”

Thermodynamic properties of chlorite CCa-2. Heat capacities, heat contents and entropies

“…The heat capacities of the clay mineral can then be calculated at any temperature. For rutile, data were provided by Shomate (1947) between 52 and 298 K, and by Robie and Hemingway (1995) between 298.15 and 520 K. These data were extracted from two different referenced works, which cover, respectively, temperature ranges lower and higher than 298.15 K. A slight difference of 0.45% of C p value was observed between heat capacities at 298.15 K. Nevertheless, the resulting error on the heat capacity of the mineral at 298.15 K, which is ±0.003%, can be neglected compared to the uncertainties on measurements of the heat capacities of the mineral. Molar heat capacity values of the chlorite C o p;m are given at selected temperatures in Table 5.…”

Thermodynamic properties of anhydrous smectite MX-80, illite IMt-2 and mixed-layer illite–smectite ISCz-1 as determined by calorimetric methods. Part I: Heat capacities, heat contents and entropies

“…Silica impurity contributions to the measured heat capacities vary between 20% and 27% for MX-80 and 7% and 8% for IMt-2 and are about 0.8% for ISCz-1. For microcline, heat capacity data were taken from Openshaw et al (1976) between 5 and 298 K and from Robie and Hemingway (1995) between 298.15 and 520 K. For kaolinite, data were taken from Robie and Hemingway (1991) between 7 and 298 K and from Robie and Hemingway (1995) between 298.15 and 520 K. For rutile, data were provided by Shomate (1947) between 52 and 298 K and by Robie and Hemingway (1995) between 298.15 and 520 K. For these latter impurities, data were extracted from two different referenced works, which cover, respectively, temperature ranges lower and higher than 298.15 K. For a given impurity (except silica), some differences were observed between heat capacities at 298.15 K. Nevertheless, the resulting errors in the heat capacity of the minerals at 298.15 K are lower than 0.03% for mixed-layer and 0.003% for illite. They are small compared to the expected maximum absolute errors on measurements of the heat capacities of the minerals, which are: 1% between 5 and 30 K; 0.05-0.1% between 30 and 100 K; 0.03% from 100 to 380 K for MX-80 and ISCz-1 and from 100 to 400 K for IMt-2 (adiabatic calorimetry measurements); and 0.1% in the range 380-520 K for MX-80 and ISCz-1 and in the 400-510 K range for IMt-2 (DSC measurements).…”