Thermodynamic properties and superconductivity of natural carrollite (CuCo2S4)
Journal Article
·
· Journal of Chemical Thermodynamics
- Brigham Young University, Provo, UT (United States)
- Arizona State University, Tempe, AZ (United States)
- Stellenbosch University, Matieland (South Africa)
- University of Tennessee, Knoxville, TN (United States)
The thermodynamic properties of natural carrollite with a formula Cu0.92Co2.07S4 are studied using low temperature heat capacity and high temperature oxidative solution calorimetry. The standard thermodynamic functions at 298.15 K are: Cp,m°, Sm°, Hm°, and Φm° are 158.48 J∙K−1∙mol−1, 176.33 J∙K−1∙mol−1, 28.40 kJ∙mol−1, and 81.07 kJ∙mol−1 with an estimated error of 1%. The enthalpies (ΔfH), entropies (ΔfS), and Gibbs energies of formation (ΔfG) from elements at 298.15 K are: −344.46 ± 12.87 kJ∙mol−1, −45.22 ± 1.81 J∙K−1∙mol−1, and −331.14 ± 1.89 J∙K−1∙mol−1. The stability of carrollite relative to the elements is demonstrated with a negative Gibbs energy (ΔGr°) of formation for several temperatures between 0 and 300 K. Furthermore, a superconductivity transition, which has been observed previously for synthetic carrollite, is confirmed by both the low temperature heat capacity and magnetization measurements.
- Research Organization:
- Univ. of California, Davis, CA (United States); Univ. of Tennessee, Knoxville, TN (United States); University of Tennessee, Knoxville, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- FG02-97ER14749; SC0021344
- OSTI ID:
- 3013120
- Alternate ID(s):
- OSTI ID: 2576771
- Journal Information:
- Journal of Chemical Thermodynamics, Journal Name: Journal of Chemical Thermodynamics Vol. 185; ISSN 0021-9614
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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