Abstract
The relative dielectric constant of a series of perovskites such as CaTi, SrTi, BaTi, PbTi, and KTa has been measured at microwave frequencies over a wide range above the Curie temperature. It was found that a Curie-Weiss law of the form is accurately obeyed where is of the order of 50 and represents the dielectric constant in the limit of infinite temperature, and that and , the Curie temperature and Curie constant, increase monotonically with increasing cation mass. consists of contributions from the electronic polarizability, temperature-independent optically active lattice vibrations, and a dominant term stemming from the finite frequency of the temperature-dependent soft mode in the limit of infinite temperature. The limiting frequency of the "soft mode" at high temperatures is estimated.
- Received 20 August 1962
DOI:https://doi.org/10.1103/PhysRev.135.A748
©1964 American Physical Society