Charge pumping and pseudopyroelectric effect in active ferroelectric relaxor-type films

Unidirectional charge flow was observed in potassium tantalum niobate, ${\mathrm{KTa}}_{0.6}$ ${\mathrm{Nb}}_{0.4}$ ${\mathrm{O}}_3$, films. These films of relaxor-type diffuse phase transition material were formed by metalorganic deposition and had a polarization gradient normal to the surface of the films. Novel charge pumping was observed in the active operation of simple two-terminal structures by excitation with periodic, strong electric fields. Such operation also showed a large pseudopyroelectric response. Effective pyroelectric coefficients as large as 2×${10}^{\mathrm{-}5}$ C/${\mathrm{cm}}^2$ °C have been obtained.