Correlation Between the Microstructure and the Electrical Properties of ZrTiO4 Ceramics

A series of ZrTiO4 (ZT) ceramics were prepared by sintering ball-milled precursor powders. Ceramics with homogenously dispersed micropores containing both low-temperature (ordered) and high-temperature (disordered) ZrTiO4 phases were achieved by sintering at 1400°C. The porosity and the morphology were modified by changing the sintering time. The impedance spectra followed the observed changes in the ceramics' microstructure. The grain boundaries' shape, rather than the grain size, has the major influence on the conductivity. The lowest value for electrical conductivity, 8.1 × 10−10 (Ω·m)−1, was obtained in the ceramics sintered at 1400°C for 4 h. This confirms the blocking effect of the imperfect grain boundaries; i.e., the defects of the grain boundaries, which were formed during the grain growth, were followed by an almost complete loss of pores.