Tetragonal and rhombohedral phase co-existence in the system : PbZrO3-PbTiO3-Pb(Fe1/5, Ni1/5, Sb1/5, Sb3/5)O3

Various compositions of xPbZrO3-yPbTiO3-zPb(Fe1/5, Ni1/5, Sb3/5)O3 piezoelectric ceramics, having a Zr/Ti ratio between 45.1/49.9 and 51.1/43.9, were prepared using the usual ceramic techniques, in the temperature range 850-1200 C. The electromechanical coupling factor, piezoelectric constant and Young's modulus were measured as a function of the Zr/Ti ratio. The results obtained are discussed on the basis of the effects of varying the Zr/Ti ratio. The effects of sintering temperature on microstructure were studied by SEM. Grain growth is enhanced by increasing the temperature. XRD 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. 17 refs.