Microstructures, dielectric, and piezoelectric properties of W/Cr co-doped Bi4Ti3O12 ceramics

Abstract

Effect of lattice occupation behavior of Li+ cations on microstructure and electrical properties of (Bi1/2Na1/2)TiO3-based lead-free piezoceramics W/Cr co-doped Bi 4 Ti 3 O 12 (BTWC) ceramics {Bi 4 Ti 3Àx W x O 12 þ x þ 0.2 wt. % Cr 2 O 3 (x ¼ 0-0.1)} with a high piezoelectricity were prepared by a conventional ceramic process, and effects of W/Cr dopant on the microstructures, dielectric, and piezoelectric properties of ceramics were explored. It is found that W 6þ modified the grain morphology and size of ceramics, promoting the forming of the regular schistose grains with a size of $10 lm in the ceramic at x ¼ 0.05. BTWC ceramics showed a continuous decrease in T c and a gradual increase in e r with the increasing W doping content. While the hard-doping of Cr 2 O 3 decreased, the TK e and tan d of ceramics available. All the ceramics keep the nature of first-order transition and displacive ferroelectrics. The d 33 and k p of BTWC ceramics were remarkably improved by the soft-doping of W 6þ . Excellent electrical properties (e.g., T c ¼ 638 C, e r ¼ 146, tan d ¼ 0.56%, TK e (500 C) ¼ 1.30 Â 10 À3 / C, s (500 C) ¼ 4.08 Â 10 À5 s, d 33 ¼ 28 pC/N, and k p ¼ 6.17%) have been achieved in Bi 4 Ti 2.95 W 0.05 O 12.05 þ 0.2 wt. % Cr 2 O 3 ceramic. Such a material can be a promising candidate for high-temperature piezoelectric applications. V C 2014 AIP Publishing LLC. [http://dx.

Influence of sintering temperatures on microstructures and electrical properties of Bi4Ti2.95W0.05O12.05+0.2wt%Cr2O3 ceramics

“…When compared to the variation in k p with sintering temperatures, Q m moves to an opposite direction. This may be explained according to their calculation formulas [10]. However, the variation in N p with sintering temperatures seems to follow the same way as the relative density of samples does (see Fig.…”

“…In this experiment, the increase in sintering temperatures induced the increase in grain size of samples, which leads to the decrease in their permittivity according to this innerstress model. On the other hand, an approximate inverse proportion relationship between T c and e r of BLSFs (in the same component system) has been proved in [10] according to Landau-Devonshire theory. The decrease in e r of samples resulted in the increase in their T c .…”

“…W/Cr co-doped Bi 4 Ti 3 O 12 ceramics with a chemical formula of Bi 4 Ti 2.95 W 0.05 O 12.05 + 0.2 wt%Cr 2 O 3 (BTWC2), were synthesized according to the traditional ceramic process described in one of our previous articles [10], and they were sintered in a sealed alumina crucible at five different temperatures of 1050 C, 1075 C, 1100 C, 1125 C and 1150 C for 2 h, especially.…”

“…10 10 V cm) and the satisfied piezoelectric constant (d 33 ! 22 pC/N) have been achieved in W/Cr co-doped Bi 4 Ti 3 O 12 ceramics [8][9][10], there are very few reports further concerning the influence of sintering temperatures on its structures and properties. Many researches have revealed that electric properties of piezoceramics can be tailored by sintering temperatures, in view of its crucial influence on the crystal structure, microstructures and other properties of ceramics [11][12][13].…”

Fracture Behaviors and Ferroelastic Deformation in W/Cr Co‐Doped Bi4Ti3O12 Ceramics

“…6,7 In this experiment, the ceramic powders were pressed into difform green bodies for sintering by using different forming dies. Then, the sintered ceramics were machined to the required samples according to the relevant test standards.…”