Tetragonal and rhombohedral phase co-existence in the system: PbZrO3-PbTiO3-Pb(Fe-1/5,Ni-1/5,Sb-3/5)O-3

Various compositions of xPbZrO(3)-yPbTiO(3)-zPb(Fe-1/5, Ni-1/5, Sb-3/5)O-3 piezoelectric ceramics, having a Zr/Ti ratio between 45.1/49.9 and 51.1/43.9, were prepared using the usual ceramics technique, in the temperature range 850-1200 degrees C. The electromechanical coupling factor (k(p)), piezoelectric constant (d(ij)) and Young's modulus (Y) are measured as a function of the Zr/Ti ratio. The obtained results are discussed on the basis of the effects of varying the Zr/Ti ratio. The effects of sintering temperature on microstructure are studied by means of a scanning electron microscope (SEM). Grain growth is enhanced by increasing temperature. X-ray diffraction demonstrated the co-existence of both tetragonal and rhombohedral phases. The lattice parameter measurements showed that tetragonal and rhombohedral unit cells of the two phases depend on the sintering temperature.