Microstructural and Electrical Characteristics of TiO.sub.3 - ZnO Piezoceramics

Ceramic materials of the Bi.sub.0.5Na.sub.0.5TiO.sub.3- xZnO (BNT - xZnO) system with the content of ZnO x = 0 and 2.0 wt.% obtained by the classical solid-state reaction method are studied. The initial powders (Bi.sub.2O.sub.3, TiO.sub.2 and Na.sub.2CO.sub.3) with a ZnO addition are milled for 10 h, calcined at 850°C for 3 h, pressed, and sintered at 1050°C for 3 h. The morphology and the microstructure of the sintered granules are studied using XRD, scanning electron microscopy, and a helium pycnometer. It is shown that the material acquires a solid solution of (Bi.sub.0.5Na.sub.0.5)TiO.sub.3 with a structure of pure perovskite and Zn.sub.2TiO.sub.4 spinel. The piezoelectric coefficient d33 after the sintering at 1050°C for the BNT ceramics amounts to 155 pC/N; in the case of BNT with 2 wt.% ZnO the value is 181 pC/N. The ZnO addition to the BNT ceramics raises the density of the material and provides an electrical conductivity of 7.48 x 10.sup.8 [Omega]* cm.