An Irreversible Thermodynamic Formalism of the Electronic Contribution to the Entropy in Metals

We have applied an irreversible thermodynamic formalism to quantify the electronic contribution to the entropy in metals and alloys. We demonstrate the utility in our proposed approach by rationalizing the entropy of phase transitions in metal-insulator, order-disorder, and allotropic transitions with current models of the vibrational and configurational entropy. Measurements of the electronic transport properties in Cu-Ni, Fe-Ni, and Fe-Cr alloys reveal the importance of considering multicarrier transport models when interpreting electronic transport properties. We generalize our approach to include the effects of the electronic entropy on the mixing thermodynamics of these alloy systems and attempt to integrate our results with conventional thermodynamic modeling by appealing to a cluster model for their configurational entropy. Finally, our work questions the idea of "thermodynamic ideality" in these alloys. We find that the entropy of mixing shows a noticeable electronic influence even when the total entropy seems unremarkable. This suggests that the short range order (S.R.O.) of atoms plays a significant role in both the solid and molten states, even when there are no dominant intermetallic compounds in these alloys.

Name thesis:degree_name

Doctoral

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Materials Science and Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2023

Author dc:creator

• Paras, Jonathan S.

Advisor dc:contributor.advisor

• Allanore, Antoine

Statement dc:rights

• In Copyright - Educational Use Permitted
• Copyright retained by author(s)

Licence dc:rights.uri

• https://rightsstatements.org/page/InC-EDU/1.0/

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/153086

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/153086