The morphotropic phase boundary in PZT solid solutions

PbZr_xTi_1-xO₃ ceramics around the morphotropic phase boundary (MPB) have been prepared under different firing conditions using the usual ceramic techniques. The phases of the compounds have been investigated with X-ray diffraction photographs. It has been found that the MPB is not a narrow and vertically straight boundary but a region whose width depends on the firing time and temperature. The microstructures of the ceramics have been studied with a scanning electron microscope and can be correlated with the firing conditions. Measurements of lattice parameters, dielectric constants and transition temperatures are reported.