Molar heat capacity and thermodynamic functions for CaTiO3

Brian F. Woodfield; Jennifer L. Shapiro; Rebecca Stevens; Juliana Boerio-Goates; Robert L. Putnam; Katheryn B. Helean; Alexandra Navrotsky

doi:10.1006/jcht.1999.0556

Molar heat capacity and thermodynamic functions for CaTiO₃

Brian F. Woodfield, Jennifer L. Shapiro, Rebecca Stevens, Juliana Boerio-Goates, Robert L. Putnam, Katheryn B. Helean, Alexandra Navrotsky

Research output: Contribution to journal › Article › peer-review

65 Scopus citations

Abstract

Calcium titanate, CaTiO₃, has appeared as a significant impurity in the synthesis of several ceramic host materials for the disposal of excess weapons grade plutonium and uranium. Previously reported heat capacities on CaTiO₃ extend only to T = 50 K. Also, the agreement of the low-temperature heat capacity results with those used to calculate the currently accepted values of the thermodynamic functions at elevated temperatures is poor near their intersection. To resolve these problems, the heat capacity of CaTiO₃ was measured from T ≈ 14 K to T ≈ 400 K using an adiabatic calorimeter. A nine-term fitting equation was found to represent adequately the low-temperature experimental heat capacities from this study and high-temperature results from the literature. It is used to extrapolate the thermodynamic data for CaTiO₃ to T = 1900 K. New values for Δ_fG^o_m and Δ_fH^o_m as a function of temperature are also tabulated.

Original language	English (US)
Pages (from-to)	1573-1583
Number of pages	11
Journal	Journal of Chemical Thermodynamics
Volume	31
Issue number	12
DOIs	https://doi.org/10.1006/jcht.1999.0556
State	Published - Dec 1999
Externally published	Yes

Keywords

CaTiO
Enthalpy of formation
Entropy
Heat capacity
Thermodynamics

ASJC Scopus subject areas

Atomic and Molecular Physics, and Optics
General Materials Science
Physical and Theoretical Chemistry

Access to Document

10.1006/jcht.1999.0556

Cite this

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title = "Molar heat capacity and thermodynamic functions for CaTiO3",

abstract = "Calcium titanate, CaTiO3, has appeared as a significant impurity in the synthesis of several ceramic host materials for the disposal of excess weapons grade plutonium and uranium. Previously reported heat capacities on CaTiO3 extend only to T = 50 K. Also, the agreement of the low-temperature heat capacity results with those used to calculate the currently accepted values of the thermodynamic functions at elevated temperatures is poor near their intersection. To resolve these problems, the heat capacity of CaTiO3 was measured from T ≈ 14 K to T ≈ 400 K using an adiabatic calorimeter. A nine-term fitting equation was found to represent adequately the low-temperature experimental heat capacities from this study and high-temperature results from the literature. It is used to extrapolate the thermodynamic data for CaTiO3 to T = 1900 K. New values for ΔfGom and ΔfHom as a function of temperature are also tabulated.",

keywords = "CaTiO, Enthalpy of formation, Entropy, Heat capacity, Thermodynamics",

author = "Woodfield, {Brian F.} and Shapiro, {Jennifer L.} and Rebecca Stevens and Juliana Boerio-Goates and Putnam, {Robert L.} and Helean, {Katheryn B.} and Alexandra Navrotsky",

note = "Funding Information: This work was supported in part by Department of Energy grant number DE-FG-07-97ER45673.",

year = "1999",

month = dec,

doi = "10.1006/jcht.1999.0556",

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AU - Woodfield, Brian F.

AU - Shapiro, Jennifer L.

AU - Stevens, Rebecca

AU - Boerio-Goates, Juliana

AU - Putnam, Robert L.

AU - Helean, Katheryn B.

AU - Navrotsky, Alexandra

N1 - Funding Information: This work was supported in part by Department of Energy grant number DE-FG-07-97ER45673.

PY - 1999/12

Y1 - 1999/12

N2 - Calcium titanate, CaTiO3, has appeared as a significant impurity in the synthesis of several ceramic host materials for the disposal of excess weapons grade plutonium and uranium. Previously reported heat capacities on CaTiO3 extend only to T = 50 K. Also, the agreement of the low-temperature heat capacity results with those used to calculate the currently accepted values of the thermodynamic functions at elevated temperatures is poor near their intersection. To resolve these problems, the heat capacity of CaTiO3 was measured from T ≈ 14 K to T ≈ 400 K using an adiabatic calorimeter. A nine-term fitting equation was found to represent adequately the low-temperature experimental heat capacities from this study and high-temperature results from the literature. It is used to extrapolate the thermodynamic data for CaTiO3 to T = 1900 K. New values for ΔfGom and ΔfHom as a function of temperature are also tabulated.

AB - Calcium titanate, CaTiO3, has appeared as a significant impurity in the synthesis of several ceramic host materials for the disposal of excess weapons grade plutonium and uranium. Previously reported heat capacities on CaTiO3 extend only to T = 50 K. Also, the agreement of the low-temperature heat capacity results with those used to calculate the currently accepted values of the thermodynamic functions at elevated temperatures is poor near their intersection. To resolve these problems, the heat capacity of CaTiO3 was measured from T ≈ 14 K to T ≈ 400 K using an adiabatic calorimeter. A nine-term fitting equation was found to represent adequately the low-temperature experimental heat capacities from this study and high-temperature results from the literature. It is used to extrapolate the thermodynamic data for CaTiO3 to T = 1900 K. New values for ΔfGom and ΔfHom as a function of temperature are also tabulated.

KW - CaTiO

KW - Enthalpy of formation

KW - Entropy

KW - Heat capacity

KW - Thermodynamics

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