Exceptional structural phase transition near room temperature in an organic–inorganic hybrid ferroelectric

Abstract

An organic–inorganic hybrid ferroelectric, (C₆H₅CH₂CH₂NH₃)₂[HgI₄], undergoes an exceptional structural phase transition near room temperature, triggered by a flip of half the organic cations and an order–disorder transition of the inorganic anions, and may be regarded as a displacive-type ferroelectric. This finding provides a new structural phase transition mechanism in molecule-based ferroelectrics.