Effect of acceptor and donor dopants on ferroelectric and piezoelectric properties of lead zirconate titanate ceramics

Abstract

PACS 61.72. Ww, 77.65.Bn, 77.80.Bh, 77.84.Dy Dielectric, ferroelectric and piezoelectric properties of Pb 1-x La x (Zr y Ti 1-y ) 1-(x/4)-(3/4)z Fe z O 3 ceramics for z = 0 to 6 mol% prepared by a mixed oxide method were investigated. Fe substitution in lead lanthanum zirconate titanate (PLZT) compositions resulted in a phase transformation from coexisting phases (ferroelectric rhombohedral (FE RH ) and ferroelectric tetragonal (FE TET )) to intensified tetragonal phase. Grain size and apparent density increased with increasing acceptor (Fe) content up to 3 mol% in the PLZT system. The optimum dielectric properties (ε RT , ε Tc and tan δ) were observed in 3 mol% Fe-doped PLZT composition and then decreased thereafter. Acceptor (Fe) substitution in the PLZT system influenced the ferroelectric remanent polarization (P r ) and spontaneous (P s ) polarization, reaching saturation at 6 mol% Fe, while the coercive field (E c ) increased up to 3 mol% Fe-doped PLZT composition. The piezoelectric properties are sensitive to acceptor (Fe) modification in the PLZT system which was proved by the decreasing trend of piezoelectric charge coefficient (d 33 ) up to 3 mol% Fe and then increasing to 6 mol% Fe while the piezoelectric planar coupling coefficient (k p ) showed a continuous decreasing trend throughout the series. Dielectric, ferroelectric and piezoelectric properties were characterized as a function of acceptor (Fe) concentration in the PLZT system for possible sensor and actuator applications.

Investigation of dielectric and piezoelectric properties of niobium-modified PLSZFT nanoceramics for sensor and actuator applications

“…The detailed fabrication of ceramics is reported elsewhere [5,10]. The batch powders were ball-milled (zirconia balls and ethanol as media for 24 h) and calcined (925 • C for 3 h) in a high purity alumina crucible.…”

“…An ideal piezoelectric ceramic could be the combination of both hard (acceptor) and soft (donor) dopants near the morphotrophic phase boundary which could be resistive as well as sensitive. Previous investigations reported that high electromechanical behaviour was found with soft doping (isovalent Ba [5] and Sr [6,7]) and hard doping (acceptors Ag [8] and Fe [9,10]). The electrical and mechanical properties of donor and/or acceptormodified PLZT depends on the nature of dopant, its concentration and its effects in stoichiometric compounds resulting in desired end products which influence the microstructure, being this a consequence of the processing route.…”

Dielectric and Raman Studies of 0.935(Bi0.5Na0.5TiO3)-0.065BaTiO3 Lead Free Ceramics

“…The average grain size is about 2 to 3 µm. It was reported in literature that for PZT and La +3 doped PZT (PLZT) based ceramics, the substitution of Ba +2 for Pb +2 generally leads to a great inhibition of grain growth [13,14]. Similar to Ba-modified leadbased ceramics, for the (1 − x)NBT-xBT ceramics, grain growth is inhibited after the introduction of BaTiO 3 into Na 0.5 Bi 0.5 TiO 3 structure.…”

Investigation of a new lead-free (0.89−x)(Bi0.5Na0.5)TiO3–0.11(Bi0.5K0.5)TiO3–xBa0.85Ca0.15Ti0.90Zr0.10O3 ceramics

“…The introduction of BCTZ does not obviously change the microstructure of BNT-BKT except for a slight decrease in the grain size in the ceramic with x = 0.16. The decrease in grain size could be attributed to the inhibition of the grain growth [16,29] induced by the introduction of a higher BCTZ content into the BNT-BKT material system, and the dense microstructure is developed in these ceramics. Fig.…”