Impedance spectroscopy analysis of zirconia:8 mol%

摘要

Porous ZrO_2:8 mol% Y_2O_3 sintered ceramics were prepared by adding graphite powder as pore former before sintering. The thermal elimination of graphite was evaluated by thermogravimetric analysis. Impedance spectroscopy analysis was carried out in the 5 Hz to 13 MHz frequency range in specimens sintered with and without pore former. The deconvolution of the impedance diagrams, [Z″(ω) x Z′(ω)] and [Z″(ω) x logf], and the numerical residuals resulting from the subtraction of normalized impedance spectroscopy diagrams measured in specimens with and without pore formers were evaluated. A comparison of the impedance diagrams of samples sintered with and without pore former shows evidence of a modification of the electrical response caused by pores. The results show the unequivocal ability of the impedance spectroscopy technique to gauge microstructural modification caused by the presence of pores in ionic conducting solids.