Sodium Bismuth Titanate‐Based Lead‐Free Piezoceramics Prepared by Aqueous Gelcasting

Abstract

Aqueous gelcasting for 0.94Bi0.5Na0.5TiO3–0.06BaTiO3 (BNBT6) lead‐free piezoceramics was investigated in this paper. A stable BNBT6 suspension with 50 vol% of solid loading and <1Pa·s of viscosity was successfully prepared when 0.5 wt% of PMAA‐NH4 was added with the pH value controlled in the range 8–10. Dehydration and desiccation of the gelled parts could be controlled easily through dipping pretreatment with a 5 wt% ammonium persulfate solution for 24 h or with a 10 wt% ammonium persulfate solution for 12 h. Scanning electron microscopy micrographs show that the BNBT6 ceramic prepared by the gelcasting route exhibits a homogeneous microstructure and a high density. Optimal piezoelectric and dielectric properties were obtained: d33=132pC/N, , tg δ=0.019, and kp=0.25.

Perspective on the Development of Lead‐free Piezoceramics

“…Many researchers have since investigated BNT–BT synthesized by different methods near the MPB composition 285–291 . The overall achieved properties of BNT–BT and of Bi‐based solid solutions are summarized in Table VI.…”

Interaction and dispersion stability of alumina suspension with PAA in N,N′-dimethylformamide

“…So the drying step is thought to be a time-consuming and tedious process. 14 Moreover, many materials show reactivity in water, such as hydrolysis reaction. The reactive species can cause inhomogeneous chemical composition of the final material.…”

Growth and electrical properties of 0.95Na0.5Bi0.5TiO3–0.05K0.5Bi0.5TiO3 lead-free piezoelectric crystal by the TSSG method

“…Since sodium bismuth titanate, Na 0.5 Bi 0.5 TiO 3 (NBT), an A-site complex perovskite ferroelectric was discovered by Smolenskii in 1960 [1,2], NBT and NBT-based solid solutions, such as (Na 0.5 Bi 0.5 )TiO 3 -(K 0.5 Bi 0.5 )TiO 3 and (Na 0.5 Bi 0.5 )TiO 3 -BaTiO 3 , have been actively investigated as possible substitute for lead-based piezoelectric materials from the viewpoint of environmental protection [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Among them, (1À x)(Na 0.5 Bi 0.5 )TiO 3 -x(K 0.5 Bi 0.5 )TiO 3 (abbreviated as (1À x)NBT-xKBT) is one of the most attractive system due to their excellent piezoelectric properties [12][13][14][15][16][17][18][19][20][21][22].…”