Pulsed neutron diffraction study of Zr-rich PZT

Pulsed neutron diffraction investigations have been performed in the ferroelectric PZT system (PbZr1-xTixO3) doped with 1 wt% of Nb2O5, as a function of both temperature and composition. The study has been made in a wide range of temperatures encompassing the three known phases in Zr-rich PZT: ferroelectric low temperature (R3c), ferroelectric high temperature (R3m) and paraelectric (Pm3m). The combination of the temperature and the composition dependence of the structural parameters allowed the determination of the special relationship, recently pointed out by Corker et al, between the octahedral strain (ζ) and the tilt angle (ω) in the ferroelectric low temperature phase (FL) of PZT. The strain-tilt coupling coefficient has been found to decrease linearly with Ti content and the composition at which ζ and ω decouple has been found to be x approx. 0.30. (author)