Direct Conversion of Heat to Electricity Using First-Order Phase Transformations in Ferroelectrics

Abstract

The discovery of alternate methods of producing energy that do not contribute to global climate change is a compelling problem of our time. This study develops a means of generating electricity from small temperature differences by exploiting a first-order ferroelectric phase transformation. The authors model the thermodynamics of energy conversion using the Landau free energy, and experimentally demonstrate the direct conversion of heat to electricity using single-crystal BaTiO${}_{3}$. A key role is played by the influence of electric field on transformation temperature, which has the effect of opening up a mixed-phase region in the temperature-entropy diagram.