Synthesis and properties of nasicon prepared from different zirconia-basedprecursors

This work reports on the synthesis and characterization of NASICON prepared from SiO2, Na3PO4. 12H(2)O and two types of zirconia: pure monoclinic ZrO2 and TZP (Tetragonal Polycrystalline Zirconia, with 3 mol% Y2O3) as raw mat erials. The classical ceramic method was used in all cases. SEM, XRD and DT A were used to follow the synthesis and sintering process, and impedance sp ectroscopy (IS) was used to study the electrical properties of sintered pel lets. Results obtained with different NASICON samples showed a significant role of composition and processing conditions on the electrical properties. Samples based on TZP, sintered at 1210 degrees C, exhibited densities Of a bout 3.20 g/cm(3) (98% of theoretical density of NASICON) and ionic conduct ivities of about 2x10(-3) S.cm(-1) at room temperature a rather interesting result when compared with data obtained with the material prepared from pu re ZrO2.