Ferroelectric phase transitions in oxides of the persovskite family
Ishchuk V. M. , Kvichko L. A. , Seminozhenko V. P. , Sobolev V. L. , Spiridonov N. A.
Anomalies have been found in the dielectric constant of YBa2Cu306 + x which are similar to the anomalies which occur during phase transitions in ferroelectric and antiferroelectric materials of the BaTi03 type.