Electrical Properties of Nb-Doped PZT 65/35 Ceramics: Influence of Nb and Excess PbO

Abstract

The effect of Nb and excess PbO on the structural and electrical properties of conventionally prepared Nb-doped PZT 65/35 ceramics has been studied in this work. It is found that, from excess PbO contents as high as 4 mol%, the solubility limit of Nb in PZT occurs below 4 mol%, while a secondary prevoskite-like phase develops in the dielectric system for a further increase of Nb content. The ferroelectric and piezoelectric properties (permittivity, ferro-paraelectric phase transition, polarization, electromechanical coefficients) of such materials are thus found to be strongly dependent on the degree of densification and structural phase development during sintering at high temperatures. In particular, the nature of the ferro-to para-electric phase transition is in these materials noted to better fit a generalized rather than Smolenskii-Isupov equation, the former being appropriate for the characterization of non-purely diffuse transitions. In nice agreement with the Bokov model, substitution of Nb 5+ for (Zr,Ti) 4+ is found to induce only poorly diffuse phase transition in these materials. The electrical properties reported in this work are in magnitude comparable to those exhibited by PZT-based materials.

Phase‐transition studies of Ba0.90Ca0.10(Ti1−xZrx)O3 ferroelectric ceramic compounds

“…Figure 2a shows the reciprocal of dielectric permittivity from the BCZT18 sample as a function of temperature for the data collected at 100 kHz, together with the corresponding fit above T max , that is, using the Curie–Weiss law that applies in NFEs 21: 1/ ε = ( T − T cw )/ C , where C is the Curie constant and T cw is the Curie–Weiss temperature. It is seen in this figure that the dielectric permittivity data follow this law, but at temperatures really well above T max , while deviating from this law by approximately 124 K towards lower temperatures.…”

Influence of diffuse phase transition on the anelastic behavior of Nb-doped Pb(Zr0.53Ti0.47)O3 ceramics

“…The effect of Nb 5+ doping on the physical properties of PZT (PZTN) is generally to decrease the coercive field and electric conductivity and increase the saturation polarization [5,6]. Also, PZTN ceramics exhibit a temperature dependence of the dielectric permittivity with a broad phase transition region, which characterize diffuse phase transition (DPT).…”

Ferroelectric, pyroelectric and dielectric properties of complex perovskite-structured Pb0.84Ba0.16(Zr0.44Ti0.40Fe0.08Nb0.08)O3 ceramics

“…[8] For the 0.84PZT-0.16BFN composition, the diffusivity (c) and diffuseness parameter (d), estimated from the slope and intercept of the dielectric data of Fig. 3b, have values of 1.902 and 7.423, respectively.…”