Abstract
An optical, dielectric, and structural study has been carried out on NaNb and the solid solution (Na,K)Nb, both single crystals and ceramics being used. No evidence for ferroelectricity in NaNb was found, and the crystal seems to be antiferroelectric in accordance with the nonpolar structure reported by Vousden. It is shown that a small addition of KNb to pure NaNb produces a new ferroelectric phase, the existence of which suggests a possible explanation of the conflicting dielectric and structural properties previously reported.
The phase diagram of NaNb-KNb is given. This, together with the optical and x-ray studies of pure NaNb, shows that the three phase transitions in NaNb are quite different in nature from the BaTi-type transitions in KNb.
- Received 12 May 1954
DOI:https://doi.org/10.1103/PhysRev.96.581
©1954 American Physical Society