Dielectric ordering of water molecules in the dipole lattice of potassium hexacyanoferrate(II) trihydrate

Abstract

The structure of potassium hexacyanoferrate(II) trihydrate (yellow prussiate) contains layers of water molecules between the layers of potassium and ferrocyanide octahedra. When the temperature drops down to 120 K, the water molecules have a tendency to rearrange. The movement of protons in molecular and individual rings occurs in a coordinated manner. The asymmetry of the ring environment leads to a significant decrease of the double-well potential barrier. The theory of coherent correlated motions of protons allows to explain the discreteness of the observed temperature anomalies of dielectric permittivity ε, thermally stimulated depolarization current j, and pyroelectric coefficient γ.