Showing papers by "Arthur D. Pelton published in 2021"

Unity of opposites for the ordered pairs and their application to manifold short-range orders in solutions within the quasichemical model

Abstract: Credible thermodynamic predictions of phase diagrams require reliable thermodynamic models for solutions. The Modified Quasichemical Model (MQM) was thus developed in well response to the credibility and reliability. However, the current MQM in the Pair Approximation (MQMPA) is only able to treat one Composition of Maximum Short-Range Ordering (CMSRO) in solutions, which is hindering its general application to solutions where multiple CMSRO may exist. The present paper develops the MQM in the Distinguishable-Pair Approximation (MQMDPA), capable of flexibly treating solutions with no CMSRO, single CMSRO and multiple CMSRO. Two entropic expressions describing the configurational entropy from pairs are proposed, and their similarity and difference resulting from the unity of opposites for an ordered pair are discussed thoroughly. With the current development, the MQMDPA is believed to be one of the trustiest thermodynamic models for solutions having various melt configurations.