Discovery of Elusive K4O6, a Compound Stabilized by Configurational Entropy of Polarons

Freysoldt C, Merz P, Schmidt M, Mohitkar S, Felser C, Neugebauer J, Jansen M (2019)

Publication Type: Journal article

Publication year: 2019

Journal

Angewandte Chemie International Edition Wiley

Book Volume: 58

Pages Range: 149-153

Journal Issue: 1

DOI: 10.1002/anie.201809409

Abstract

Synthesis of elusive K4O6 has disclosed implications of crucial relevance for new solid materials discovery. K4O6 forms in equilibrium from K2O2 and KO2, in an all-solid state, endothermic reaction at elevated temperature, undergoing back reaction upon cooling to ambient conditions. This tells that the compound is stabilized by entropy alone. Analyzing possible entropic contributions reveals that the configurational entropy of “localized” electrons, i.e., of polaronic quasi-particles, provides the essential contribution to the stabilization. We corroborate this assumption by measuring the relevant heats of transformation and tracking the origin of entropy of formation computationally. These findings challenge current experimental and computational approaches towards exploring chemical systems for new materials by searching the potential energy landscape: one would fail in detecting candidates that are crucially stabilized by the configurational entropy of localized polarons.

Involved external institutions

Max-Planck-Institut für Eisenforschung GmbH (MPIE) / Max Planck Institute for Iron Research

Germany (DE) Max-Planck-Institut für Chemische Physik fester Stoffe (MPI CPfS) / Max Planck Institute for Chemical Physics of Solids

Germany (DE)

How to cite

APA:

Freysoldt, C., Merz, P., Schmidt, M., Mohitkar, S., Felser, C., Neugebauer, J., & Jansen, M. (2019). Discovery of Elusive K4O6, a Compound Stabilized by Configurational Entropy of Polarons. Angewandte Chemie International Edition, 58(1), 149-153. https://doi.org/10.1002/anie.201809409

MLA:

Freysoldt, Christoph, et al. "Discovery of Elusive K4O6, a Compound Stabilized by Configurational Entropy of Polarons." Angewandte Chemie International Edition 58.1 (2019): 149-153.

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