Mixed conduction and chemical diffusion in a Pb(Zr-0.53,Ti-0.47)O-3 buried capacitor structure

作者：Donnelly Niall J^*; Randall Clive A

来源：Applied Physics Letters, 2010, 96(5): 052906.

DOI：10.1063/1.3302452

• capacitors
• ceramics
• dielectric materials
• diffusion
• electrochemical impedance spectroscopy
• equivalent circuits
• ionic conductivity
• lead compounds
• mixed conductivity
• niobium compounds
• platinum

Impedance spectroscopy is performed on a buried capacitor structure composed of a PZT-0.75% Nb ceramic with platinum electrodes. The ionic and electronic conductivities (sigma(ion),sigma(elec)) are extracted from the impedance spectra using an equivalent circuit based on the premise of mixed conduction. In the temperature range 500-700 degrees C, a change in local pO(2) mainly affects sigma(elec), suggesting that the samples are ionically compensated, i.e., [V-O(center dot center dot)]=[V-Pb(')]. The chemical diffusion coefficient, D approximate to, is obtained by a conductivity relaxation technique assuming two-dimensional diffusion geometry. In comparison to BaTiO3, or SrTiO3, the chemical diffusivity is found to be relatively high, D approximate to=2.0x10(-4) cm(2) s(-1) (700 degrees C, in air).

• 出版日期2010-2-1