The influence of Zr/Ti content on the morphotropic phase boundary in the PZT–PZN system

A quantitative structural investigation was carried out on (1 − y)PbZrxTi1−xO3–yPbZn1/3Nb2/3O3 where y = 0.1 and 0.2 ((1 − y)PZT–yPZN). High resolution XRD data have been used for quantitative phase analysis. The nominal compositions were prepared by a two-step low temperature calcining solid-state method. The sintered samples show an average grain size of 1–2 μm. It is demonstrated that the increase in the concentration of PZN leads to the shift of the morphotropic phase boundary (MPB) of PZT towards the PbZrO3 end member. In the present work, an effort has been made to quantitatively determine the MPB phase contents and to regain the coexistence of tetragonal and monoclinic phases by varying the value of x (i.e. Zr/Ti ratio). The width of the MPB becomes considerably larger for y = 0.10 and 0.20 as compared to pure PZT. This is attributed to the considerably lower grain size of our samples resulting from the adopted preparation method.