Theoretical prediction of a charge-transfer phase transition

Hiroko Tokoro,Rei Fujiwara,Kouji Chiba,Marie Yoshikiyo,Asuka Namai,Shin-Ichi Ohkoshi

doi:10.1038/s41598-017-18213-0

Hiroko Tokoro, Rei Fujiwara + Show 4 more

Open Access

https://doi.org/10.1038/s41598-017-18213-0

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Journal: Scientific Reports	Publication Date: Jan 11, 2018
Citations: 26	License type: open-access

Affiliation: University of Tsukuba, The University of Tokyo

Abstract

Phase transition materials are attractive from the viewpoints of basic science as well as practical applications. For example, optical phase transition materials are used for optical recording media. If a phase transition in condensed matter could be predicted or designed prior to synthesizing, the development of phase transition materials will be accelerated. Herein we show a logical strategy for designing a phase transition accompanying a thermal hysteresis loop. Combining first-principles phonon mode calculations and statistical thermodynamic calculations considering cooperative interaction predicts a charge-transfer phase transition between the A–B and A+–B− phases. As an example, we demonstrate the charge-transfer phase transition on rubidium manganese hexacyanoferrate. The predicted phase transition temperature and the thermal hysteresis loop agree well with the experimental results. This approach will contribute to the rapid development of yet undiscovered phase transition materials.

Highlights

IntroductionWe consider a strategy to predict phase transitions
Questions remain in phase transition materials research
We considered whether a thermal hysteresis loop appears in the present system

Summary

Introduction

We consider a strategy to predict phase transitions. Estimations of thermodynamic parameters, such as enthalpy, entropy, and Gibbs free energy, are necessary to predict phase transitions. The cooperative interaction inside the crystal at the phase transition must be evaluated to predict a thermal hysteresis loop. We predict a charge-transfer phase transition on rubidium manganese hexacyanoferrate as a demonstration system using a combination method between first-principles calculations and statistical thermodynamic calculations. We considered a flowchart of a logical strategy to predict the charge-transfer phase transition between the A–B phase (α-phase) and its valence isomer where one electron transfers from A to B, i.e., A+– B− phase (β-phase) (Fig. 1). The detail explanation of the strategy mentioned above are described in the Methods section

Methods

Results

Conclusion