The internal electric fieldgradient in antiferroelectric PbZrO3 studied by perturbed angular correlations
The internal electric fieldgradient (EFG) at the Zr-site in antiferroelectric polycristalline PbZrO3 has been investigated as a function of temperature by time differential angular correlation measurements. For the application of this technique PbZrO3 was doped with small amounts of radioactive181Hf.In the antiferroelectric phase of PbZrO3 the EFG decreases continously with increasing temperature and exhibits a sharp discontinuity at 230 °C, the Curie point of the compound. In the cubic phase a small remaining EFG is observed which is probably caused by lattice imperfections in the source.The antiferroelectric distortion of the lattice decreases slightly when the temperature approaches the Curie point, as shown by the temperature dependence of the asymmetry parameter of the EFG.The measured EFG at room temperature is compared with the result of a lattice sum calculation.