Synthesis of lead nickel niobate-lead zirconate titanate solid solutions by a B-site precursor method

A modified processing method for lead nickel niobate-lead zirconate titanate (Pb(Ni1/3Nb2/3)O-3-Pb(Zr,Ti)O-3, PNN-PZT) solid solutions is presented. This method is based on the high-temperature synthesis of a precursor that contains all the B-site cations (Ti, Zr, Ni, and Nb). This synthesis yields a diphasic mixture that contains a ZrTiO4-like phase and a rutile-like phase. Both phases exhibit a cationic valence of 4; thus, it is concluded that the mixing of Ni and Nb cations is adequate for the preparation of PNN-PZT solid solutions. Indeed, a pure perovskite phase has been obtained after calcination with lead oxide for compositions that contain 40 and 50 mol% PNN. Moreover, their electromechanical properties have been shown to be superior to values reported for standard columbite routes. This conclusion has been interpreted in terms of enhanced chemical homogeneity.