Thermodynamics of the lanthanide trifluorides. I. The heat capacity of lanthanum trifluoride, LaF/sub 3/ from 5 to 350/sup 0/K and enthalpies from 298 to 1477/sup 0/K

Journal Article · Sat Jul 01 04:00:00 EDT 1978 · J. Chem. Phys.; (United States)

OSTI ID:7063773

Lyon, W G; Osborne, D W; Flotow, H E; Grandjean, F; Hubbard, W N; Johnson, G K

The heat capacity of a sample of LaF/sub 3/ was determined in the temperature range 5--350/sup 0/K by aneroid adiabatic calorimetry and the enthalpy from 298.15 to 1477/sup 0/K by drop calorimetry. The heat capacity at constant pressure C/sup 0//sub p/(298.15/sup 0/K), the entropy S/sup 0/ (298.15/sup 0/K), the enthalpy (H/sup 0/ (298.15/sup 0/K)-H/sup 0/ (0)) and the Planck function -(G/sup 0/ (298.15/sup 0/K)-H/sup 0/ (0))/298.15/sup 0/K; were found to be (90.29 +- 0.09) J /sup 0/K/sup -/1xmole/sup -/1, (106.98 +- 0.11) J /sup 0/K/sup -/1xmole/sup -/1, (16717 +- 17) J mole/sup -/1, and (50.91 +- 0.05) J /sup 0/K/sup -/1xmole/sup -/1. The thermal functions from the present research were extended up to the melting temperature (1766/sup 0/K) by combination with previously published results. The anomalously high heat capacity from about 1100 to 1766/sup 0/K is discussed.

• Research Organization: Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
• OSTI ID: 7063773
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 69:1; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360000* -- Materials
ENTHALPY
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HIGH TEMPERATURE
LANTHANUM COMPOUNDS
LANTHANUM FLUORIDES
LOW TEMPERATURE
MEDIUM TEMPERATURE
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
SPECIFIC HEAT
THERMODYNAMIC PROPERTIES
VERY LOW TEMPERATURE