Thermodynamic properties of two metal-rich tantalum sulfides: Ta/sub 2/S and Ta/sub 6/S

Journal Article · Fri Jun 01 00:00:00 EDT 1984 · J. Solid State Chem.; (United States)

DOI:https://doi.org/10.1016/0022-4596(84)90233-0· OSTI ID:6676653

Harbrecht, B U; Schmidt, S R; Franzen, H F

The incongruent vaporization reactions of Ta/sub 2/S and Ta/sub 6/S have been investigated by mass-loss effusion in the temperature range 1576 to 1902 K. By extrapolation of P/sub s/(obs) to equilibrium the enthalpies of the reactions 3/2 Ta/sub 2/S(s) = 1/2 Ta/sub 6/S (S) + S(g) and Ta/sub 6/S = 6 Ta(s) + S(g) wee found to be ..delta..H/sub 29//sup 80//R = 53.9(0.3) X 10/sup 3/ K and ..delta..H/sub 298//sup 0//R = 58.1(0.4) X 10/sup 3/ K, respectively. Comparison between the above values, determined by a 2nd law treatment, and 3rd law values was used to derive fef (free energy function) values for Ta and S in the compounds. These postulated fef's, which apply only to the elements as present in the compounds measured, are compared to tabulated quantities for the pure solid elements to provide a criterion for 2nd and 3rd law evaluation.

• Research Organization: Ames Lab., IA
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6676653
• Journal Information: J. Solid State Chem.; (United States), Vol. 53:1
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
TANTALUM SULFIDES
THERMODYNAMIC PROPERTIES
EXPERIMENTAL DATA
TEMPERATURE EFFECTS
CHALCOGENIDES
DATA
INFORMATION
NUMERICAL DATA
PHYSICAL PROPERTIES
SULFIDES
SULFUR COMPOUNDS
TANTALUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
400201* - Chemical & Physicochemical Properties