Temperature dependent polariton measurements in BaTiO₃

Abstract

Polariton techniques are used to determine the temperature dependence of all three A1 modes between room temperature and Tc = 134°C in the ferroelectric phase of BaTiO3. The results shows that there is a large difference between the clamped dielectric constant, ε{lunate}(0), determined from these results and ε{lunate}(0) determined from microwave capacitance techniques. It is argued that, while soft modes in displacive ferroelectrics are the driving force for the transition, other oscillators play an important role in low frequency dielectric behavior. © 1973.