High-temperature calorimetric measurements on RE.sub.2TeO.sub.6

The ternary compounds of Gd.sub.2TeO.sub.6 (s) and Er.sub.2TeO.sub.6 (s) were prepared by solid-state route and characterized by XRD, ICP-AES and ICP-MS techniques. Enthalpy measurements were taken on these compounds by inverse drop calorimetric method by using a high-temperature differential calori...

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Bibliographic Details
Published in:Journal of thermal analysis and calorimetry 2020-11, Vol.142 (3), p.1261
Main Authors: Kandan, R, Jain, Ashish, Venkatesh, P, Prabhakara Reddy, Bandi
Format: Article
Language:English
Subjects:
Calorimetry
Measurement
Thermodynamics
Online Access:Get full text
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Summary:The ternary compounds of Gd.sub.2TeO.sub.6 (s) and Er.sub.2TeO.sub.6 (s) were prepared by solid-state route and characterized by XRD, ICP-AES and ICP-MS techniques. Enthalpy measurements were taken on these compounds by inverse drop calorimetric method by using a high-temperature differential calorimeter over the temperature region 669-1272 K. The measured enthalpy increment values of these compounds were fitted to four term nonlinear polynomial functions in temperature using least-squares method. With the fitted equations, other thermodynamic function such as heat capacity, entropy and free energy functions have been computed in the temperature range 298-1300 K. The derived free energy functions of RE.sub.2TeO.sub.6 (RE = Gd, Er), from enthalpy increments measurements were combined with the standard Gibbs energies of formation of RE.sub.2TeO.sub.6 (RE = Gd, Er), derived from vapor pressure measurement, to obtain [Formula omitted] of Gd.sub.2TeO.sub.6 (s) and Er.sub.2TeO.sub.6 (s).
ISSN:1388-6150
1588-2926
DOI:10.1007/s10973-020-09567-1