Details
| Original language | English |
|---|---|
| Article number | 479 |
| Number of pages | 21 |
| Journal | Entropy |
| Volume | 24 |
| Issue number | 4 |
| Early online date | 29 Mar 2022 |
| Publication status | Published - Apr 2022 |
Abstract
The term thermal capacity appears to suggest a storable thermal quantity. However, this claim is not redeemed when thermal capacity is projected onto “heat”, which, like all energy forms, exits only in transit and is not a part of internal energy. The storable thermal quantity is entropy, and entropy capacity is a well-defined physical coefficient which has the advantage of being a susceptibility. The inverse of the entropy capacity relates the response of the system (change of temperature) to a stimulus (change of entropy) such as the fluid level responses to a change in amount of fluid contained in a vessel. Frequently, entropy capacity has been used implicitly, which is clarified in examples of the low-temperature analysis of phononic and electronic contributions to the thermal capacity of solids. Generally, entropy capacity is used in the estimation of the entropy of a solid. Implicitly, the thermoelectric figure of merit refers to entropy capacity. The advantage of the explicit use of entropy capacity comes with a descriptive fundamental understanding of the thermal behaviour of solids, which is made clear by the examples of the Debye model of phonons in solids, the latest thermochemical modelling of carbon allotropes (diamond and graphite) and not least caloric materials. An electrocaloric cycle of barium titanate close to its paraelectric–ferroelectric phase transition is analysed by means of entropy capacity. Entropy capacity is a key to intuitively understanding thermal processes.
Keywords
- barium titanate, Debye model, diamond, entropy capacity, graphite, heat capacity, phase transition, reaction entropy, Sommerfeld coefficient, susceptibility
ASJC Scopus subject areas
- Computer Science(all)
- Information Systems
- Mathematics(all)
- Mathematical Physics
- Physics and Astronomy(all)
- Physics and Astronomy (miscellaneous)
- Engineering(all)
- Electrical and Electronic Engineering
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Entropy, Vol. 24, No. 4, 479, 04.2022.
Research output: Contribution to journal › Review article › Research › peer review
}
TY - JOUR
T1 - On the Thermal Capacity of Solids
AU - Feldhoff, Armin
N1 - Funding Information: The publication of this article was funded by the Open Access Fund of Leibniz University Hannover.
PY - 2022/4
Y1 - 2022/4
N2 - The term thermal capacity appears to suggest a storable thermal quantity. However, this claim is not redeemed when thermal capacity is projected onto “heat”, which, like all energy forms, exits only in transit and is not a part of internal energy. The storable thermal quantity is entropy, and entropy capacity is a well-defined physical coefficient which has the advantage of being a susceptibility. The inverse of the entropy capacity relates the response of the system (change of temperature) to a stimulus (change of entropy) such as the fluid level responses to a change in amount of fluid contained in a vessel. Frequently, entropy capacity has been used implicitly, which is clarified in examples of the low-temperature analysis of phononic and electronic contributions to the thermal capacity of solids. Generally, entropy capacity is used in the estimation of the entropy of a solid. Implicitly, the thermoelectric figure of merit refers to entropy capacity. The advantage of the explicit use of entropy capacity comes with a descriptive fundamental understanding of the thermal behaviour of solids, which is made clear by the examples of the Debye model of phonons in solids, the latest thermochemical modelling of carbon allotropes (diamond and graphite) and not least caloric materials. An electrocaloric cycle of barium titanate close to its paraelectric–ferroelectric phase transition is analysed by means of entropy capacity. Entropy capacity is a key to intuitively understanding thermal processes.
AB - The term thermal capacity appears to suggest a storable thermal quantity. However, this claim is not redeemed when thermal capacity is projected onto “heat”, which, like all energy forms, exits only in transit and is not a part of internal energy. The storable thermal quantity is entropy, and entropy capacity is a well-defined physical coefficient which has the advantage of being a susceptibility. The inverse of the entropy capacity relates the response of the system (change of temperature) to a stimulus (change of entropy) such as the fluid level responses to a change in amount of fluid contained in a vessel. Frequently, entropy capacity has been used implicitly, which is clarified in examples of the low-temperature analysis of phononic and electronic contributions to the thermal capacity of solids. Generally, entropy capacity is used in the estimation of the entropy of a solid. Implicitly, the thermoelectric figure of merit refers to entropy capacity. The advantage of the explicit use of entropy capacity comes with a descriptive fundamental understanding of the thermal behaviour of solids, which is made clear by the examples of the Debye model of phonons in solids, the latest thermochemical modelling of carbon allotropes (diamond and graphite) and not least caloric materials. An electrocaloric cycle of barium titanate close to its paraelectric–ferroelectric phase transition is analysed by means of entropy capacity. Entropy capacity is a key to intuitively understanding thermal processes.
KW - barium titanate
KW - Debye model
KW - diamond
KW - entropy capacity
KW - graphite
KW - heat capacity
KW - phase transition
KW - reaction entropy
KW - Sommerfeld coefficient
KW - susceptibility
UR - http://www.scopus.com/inward/record.url?scp=85128292074&partnerID=8YFLogxK
U2 - 10.3390/e24040479
DO - 10.3390/e24040479
M3 - Review article
AN - SCOPUS:85128292074
VL - 24
JO - Entropy
JF - Entropy
SN - 1099-4300
IS - 4
M1 - 479
ER -