Grain-size dependence of piezoelectric properties in thermally annealed BaTiO₃ ceramics

Abstract

BaTiO 3 ceramics with grain sizes of 4.726.1¯m were fabricated using 100 and 300 nm BaTiO 3 powders by employing a two-step sintering (TSS) or conventional one-step sintering (CS) method. Polished and cut BaTiO 3 samples were annealed for the recovery and relaxation of mechanical-processing-induced surface damage and lattice strain, and the piezoelectric properties were investigated. TSS-BaTiO 3 ceramics annealed at 1000°C for 1 h with a grain size of 4.9¯m exhibited an excellent piezoelectric property of d 33 = 529 pC/N, while the d 33 value of CS-BaTiO 3 ceramics annealed at 1200°C for 8 h with a grain size of 26.1¯m was 272 pC/N. Besides the excellent piezoelectric properties of the fine-grained BaTiO 3 ceramics, the performance of the coarse-grained ceramics was higher than previously reported. The observed superior piezoelectric and electromechanical properties in annealed samples despite the increase in grain size suggested that the effect of annealing was more crucial than that of grain size.

Phase evolution and <110>‐orientation mechanism in RTGG‐processed BaTiO3 ceramics with electrical properties

“…The sintered ceramics were polished and cut into samples with plate‐type geometry (2.5 × 2.5 × 0.4 mm 3 ), and then they were annealed at 1150°C‐4 hours for the recovery of the mechanical‐processing‐induced surface‐damaged layers and relaxation of mechanical stress 2,3 . The gold (Au) electrodes were coated on both surfaces of the annealed samples by sputtering and heated at 300°C for 10 minutes.…”

“…Due to the growing concern in the toxicity of lead and lead‐oxide generated from the manufacturing, processing, and disposal of the products and/or devices containing lead‐based piezoelectric ceramics, a huge interest in the fabrication of high‐performance lead‐free piezoelectric ceramics has been generated over the past two decades 1 . BaTiO 3 is a typical ferroelectric material with appreciably large piezoelectric properties 2,3 and it is also one of the important end members of various lead‐free candidate piezoelectric systems such as BiFeO 3 ‐BaTiO 3 system doped with BiGaO 3 or Bi(Zn 0.5 Ti 0.5 )O 3 , 4 (Bi 0.5 Na 0.5 )TiO 3 ‐BaTiO 3 ‐(K 0.5 Na 0.5 )NbO 3 system, 5 (Bi 0.5 Na 0.5 )TiO 3 ‐(Bi 0.5 K 0.5 )TiO 3 ‐BaTiO 3 system, 6,7 and (Bi 0.5 K 0.5 )TiO 3 ‐BaTiO 3 ‐Bi(Mg 0.5 Ti 0.5 )O 3 ‐BiFeO 3 system, 8 which possess a morphotropic phase boundary with piezoelectric properties higher than those of the end members.…”

Effects of AC- and DC-bias field poling on piezoelectric properties of Bi-based ceramics

“…The maximum phase angle of almost 90°(perfectly poled) was reported for the BT ceramics, 19) which are ferroelectrically soft materials with a low coercive field and low charged defect concentration. The effective domain switching by DC-bias field poling, however, is difficult to achieve in the Bi-based materials, because of their high leakage current density and/or defect dipoles.…”

On the origin of grain size effects in Ba(Ti0.96Sn0.04)O3 perovskite ceramics

“…The permittivity of BaTiO3 ceramics generally shows a peak value around the grain size of 1μm, regardless of the raw materials and sintering methods used [8,[17][18]. The origin of the permittivity peak has been commonly attributed to the maximum density and mobility of 90º domain walls [6,8,[17][18]24,27].…”

“…One concerns the investigation of ferroelectric properties in nanometer-scale structures and it is devoted to clarifying the size limits of ferroelectricity [12][13][14][15][16]. The other aspect is mainly related to the understanding of the grain size dependence of dielectric, piezoelectric and ferroelectric/ferroelastic behavior in bulk systems, aimed at obtaining desired properties by appropriate tailoring the grain size [4, 6,9,10,[17][18][19][20][21][22][23][24][25].…”