Zentropy

This book compiles selected publications authored or co-authored by the editor to present a comprehensive understanding of following topics: (1) fundamentals of thermodynamics, Materials Genome(R), and zentropy theory; (2) zentropy theory for prediction of positive and negative thermal expansions; (3) density functional theory and CALPHAD modeling; (4) computational tools; and (5) applications of computational thermodynamics. It is noted that while entropy at one scale is well represented by standard statistical mechanics in terms of probability of individual configurations at that scale, the theory capable of counting total entropy of a system from different scales is lacking. The zentropy theory provides a nested form for configurational entropy enabling multiscale modeling to account for disorder and fluctuations from the electronic scale based on quantum mechanics to the experimental scale based on statistical mechanics using free energies of individual configurations rather than their total energies in standard statistical mechanics. The predictions from the zentropy theory demonstrate remarkable agreements with experimental observations for magnetic transitions and associated emergent behaviors of strongly correlated metals and oxides, including singularity and instability at critical points and positive and negative thermal expansions, without the need of additional truncated models and fitting model parameters beyond density function theory. This paves the way to provide the predicted phase equilibrium data for high throughput predictive CALPHAD modeling of complex material systems, and those individual configurations may thus be considered as the genomic building blocks of individual phases in the spirit of Materials Genome(R).

Zi-Kui Liu is the Dorothy Pate Enright Professor in the Department of Materials Science and Engineering at the Pennsylvania State University, USA. He obtained his BS from Central South University, China, MS from the University of Science and Technology Beijing, China, and PhD from KTH Royal Institute of Technology, Sweden. He was a research associate at the University of Wisconsin-Madison and a senior research scientist at QuesTek Innovations LLC. He has been at the Pennsylvania State University since 1999, the editor-in-chief of CALPHAD journal since 2001, and the president of CALPHAD Inc. since 2013. Dr Liu coined the term ＂Materials Genome(R)＂ in 2002. He is a fellow of TMS and ASM International and has served as the president of ASM International and a member of the ASM International Board of Trustees and the TMS Board of Directors. He has graduated 31 PhD students and published over 600 papers.