Estimation of Electronic Entropy Contributions to Oxygen Vacancy Formation Reaction in Nonstoichiometric Oxides via Analysis of Electronic Structure Properties

C.R.A. Cole
University of Florida,
United States

Keywords: entropy, thermodynamics, solar energy conversion and storage

Summary:

publication description The primary motivation of this work is to develop a method through which the entropy change of oxygen vacancy formation may be computed from first principles for strongly correlated metal oxides which exhibit intrinsic spin polarization. Namely, a methodology via which the electronic structure may be utilized to predict electronic entropy contributions to the overall free energy change. Leveraging electronic structure properties facilitates the process by circumventing the need for extensive combinatorics and statistical methods which are conventional approaches for entropy calculations within the realm of statistical physics. Nonstoichiometric cerium dioxide (CeO2) and the manganite perovskites (AMnO3) form a prototypical composition space meeting the criteria above and possessing a high degree of versatility with applications ranging from electrocatalysis and solar thermochemical energy storage to electronic and magnetic devices. The acquisition of a fundamental understanding of the mechanisms governing entropy in these materials would enhance the rate at which they may be optimized and tailored for current applications and potentially enable the discovery of novel applications for which they are ideal candidates.