NONLINEARITY AND DIELECTRIC LOSSES IN POTASSIUM TANTALATE.

The temperature and bias field dependence of dielectric permittivity and dynamic nonlinearity in monocrystalline potassium tantalate are investigated over the temperature range 4. 2-7. 8 deg K. It is found that in sufficiently perfect KTaO//3 crystals there is no dielectric permittivity maximum at low temperatures. The effect of pre-electrode layers and volume space charge on dielectric properties of the compound was found to be strong. Chemical etching does not completely eliminate the dielectric hysteresis found in KTaO//3 crystals. The significant effect of volume properties on dielectric characteristics was confirmed by measurements of tan delta in the same KTaO//3 crystals.