Dielectric and thermal properties of relaxation ferroelectrics at low temperatures

Changes in dielectric constant with temperature and the behaviour of thermal conductivity and specific heat in relaxation ferroelectric crystals are similar to glasses. The consideration of characteristic anomalies in the dielectric constant using the tunneling state model gives reasonable results for T ⪅ 1 K with a constant density of states. No confirmation for the presence of any energy-dependent density of tunneling states at higher temperatures can be found.