Effects of Barium Substitution on Perovskite Formation, Dielectric Properties, and Diffuseness Characteristics of Lead Zinc Niobate Ceramics

Abstract

Perovskite-phase developments in partially/fully substituted (Ba,Pb)(Zn 1/3 Nb 2/3 )O 3 , synthesized via B-site precursor routes, were investigated. The pyrochlore structure, present at no barium content, was immediately replaced by perovskite with a small amount (>8 at.%) of barium substitution. Variations in the lattice parameters of the pyrochlore and perovskite structures were studied. The weak-field radio-frequency dielectric constants and losses of the system ceramics were examined. A highest maximum dielectric constant of 9000 (76°C, 1 MHz) was observed at 8 at.% barium substitution. The dielectric-constant spectra were analyzed further in terms of diffuseness characteristics (e.g., diffuseness exponent and degree of diffuseness). The dielectric hysteresis loops of the ceramics were measured. The microstructures of the sintered ceramics also were observed.

Impact of Ba2+ on Structure and Piezoelectric Properties of PMN–PZN–PNN–PT Ceramics Near the Morphotropic Phase Boundary

“…(a)]. A similar effect appeared in many other samples due to isovalent replacement of Pb 2+ cations in the A‐position . For example, in Ref.…”

“…A similar effect appeared in many other samples due to isovalent replacement of Pb 2+ cations in the A-position. [21][22][23]52,53 For example, in Ref. [53] it is mentioned that adding Sr (an electron structure analogue of Ba) to PZT ceramics results in complication of the domain structure and significant reduction of the domain size.…”

“…[21][22][23]52,53 For example, in Ref. [53] it is mentioned that adding Sr (an electron structure analogue of Ba) to PZT ceramics results in complication of the domain structure and significant reduction of the domain size. When barium was added to (Pb 0.94Àx La 0.04-Ba x )[(Zr 0.60 Sn 0.40 ) 0.84 Ti 0.16 ]O 3 ceramics, partitioning of the antiferroelectric domains of micrometer size into ensembles of nanodomains was observed, 54 resulting in a transition from antiferroelectric to relaxor ferroelectric.…”

Probing local structure of pyrochlore lead zinc niobate with synchrotron x-ray absorption spectroscopy technique

“…Moreover, PZN in perovskite phase can also be stabilized by partial substitution on A-or B-site cations using, e.g., BaTiO 3 , SrTiO 3 , PbTiO 3 , and PbZrO 3 as matrixes. 37,38 The substituted A-site cations with spherical shape replace Pb 2þ cations and the substituted B-site cations with high valence replace Zn 2þ cations help decreasing the steric hindrance of Pb 2þ lone pair and the mutual interaction between Pb 2þ lone pair and Zn 2þ cation. While these PZN preparation methods are useful for enhancing the stability of perovskite structure and increasing the amount of perovskite phase, the dielectric properties are still not as good as those of PZN single crystal obtained from PbO flux method.…”

Effect of barium on the structure and dielectric properties of multicomponent ceramics based on ferroelectric relaxors

“…The intergranular fracture in the unmodified material may be due to the presence of the pyrochlore phase, which may be concentrated on grain boundaries in the form of intergranular inclusions (Fig. 2a, top left corner) [17], reducing the intergranu lar bonding strength. Figure 3 shows the ε/ε 0 (Е) curves of the modified and unmodified samples.…”