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

Abstract

High density ceramic samples of mPb(Mg 1/3 Nb 2/3 ) ⋅ yPb(Zn 1/3 Nb 2/3 ) ⋅ nPb(Ni 1/3 Nb 2/3 ) ⋅ xPbTiO 3 (m = 0.4541, y = 0.0982, n = 0.1477, x = 0.3) solid solutions, unmodified and barium modified, with the composition lying in a morphotropic phase region, have been prepared by a conventional ceramic processing technique. We demonstrate that barium substitution for 5% of the lead on the A site allows one to obtain ceramics containing no pyrochlore phase. Modification with barium shifts the solid solution from the mor photropic to a tetragonal phase region. In addition, barium doping increases the average grain size of the ceramic from 2-3 to 3-4 μm and changes the type of fracture from intergranular to mixed (intergranular and transgranular). Modification with barium increases the relative dielectric permittivity ε/ε 0 (at E = 0) of the material by more than a factor of 2 (from 4300 to 9100). We conclude that materials based on the ceramics studied can find practical application and examine ways of further improving their piezoelectric performance.

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

“…Earlier it was shown that the introduction of 5 mol% Ba 2+ in PZN–PMN–PNN–PT leads to stabilization of the perovskite structure (the traces of pyrochlore phase disappear on X‐ray diagrams), changes in the phase composition of the studied ceramics, significant increase in the values of their piezoelectric and dielectric responses and modifications of microstructure . A preliminary phase diagram of this system with variation in the barium content was constructed .…”

“…In addition, the modification by Ba 2+ cations contributes to changing the grain structure, smearing the temperature maximum of permittivity e/e 0 and enhancing the relaxor properties of the materials. [22][23][24][25][26] Earlier it was shown that the introduction of 5 mol% Ba 2+ in PZN-PMN-PNN-PT leads to stabilization of the perovskite structure (the traces of pyrochlore phase disappear on X-ray diagrams), changes in the phase composition of the studied ceramics, significant increase in the values of their piezoelectric and dielectric responses 27 and modifications of microstructure. 28 A preliminary phase diagram of this system with variation in the barium content was constructed.…”

Low- and high-field electromechanical responses of relaxor-based multicomponent ceramics for application in multiregime actuators

“…The object of the experimental study was ceramics of Pb 0:95 -Ba 0:05 (Mg 1=3 Nb 2=3 ) 0:471 (Zn 1=3 Nb 2=3 ) 0:102 (Ni 1=3 Nb 2=3 ) 0:152 Ti 0:275 O 3 . The choice of such a cumbersome composition was made on the basis of comprehensive preliminary experimental studies [32][33][34][35][36][37] and was caused by a number of factors. First, this solid solution is located near the MPB, which separates the pseudocubic and tetragonal phases.…”

Phase equilibria and electrical properties of barium-containing relaxor-based solid solutions

“…Samples for this inves tigation were prepared by solid state reactions via a columbite route, as described in detail elsewhere [15], and were sintered by a standard ceramic processing technique. To optimize the sintering conditions in order to ensure high purity of samples and maximize their density, we studied the effect of t sint on the phase composition, structure, and density of the solid solu tions: t sint = 1180-1200°C (2 h).…”

“…A preliminary study concerned with the effect of modification with Ba 2+ (x) on the structure, micro structure, and electrical properties of solid solutions in the morphotropic region of the ceramics investigated was reported previously [15]. It has been shown that barium substitution for 5 mol % Pb on the A site shifts the composition of the solid solution from the mor photropic region to the tetragonal (T) phase field and increases its relative dielectric permittivity ε/ε 0 by more than a factor of 2 (from 4300 to 9100).…”