Domain Structure and Enhanced Electrical Properties in Sodium Bismuth Titanate Ceramics Sintered from Crystals with Different Morphologies

Abstract

Sodium bismuth titanate (Na 0.5 Bi 0.5 TiO 3 , NBT) crystals with different morphology, wires, plates and cubes, were synthesized by hydrothermal method. The domain structure in as-synthesized poled NBT ceramics was observed. The results demonstrate that the domain width of the poled NBT ceramics sintered from wire crystals is slightly larger than that of the NBT ceramics sintered from cube crystals, while the NBT ceramics sintered from plate crystals possess the largest domain width. In particular, the poled NBT ceramics sintered from plate crystals exhibit the optimum piezoelectric coefficient and remnant polarization of 87 pC/N and 36.7 lC/cm 2 , respectively, which are 55% and 37% higher than those of the NBT ceramics sintered from cube crystals. The expanded domain width and large grain size are responsible for the improvement of ferroelectric, piezoelectric, and dielectric properties in NBT ceramics.

Morphology control and large piezoresponse of hydrothermally synthesized lead-free piezoelectric (Bi0.5Na0.5)TiO3 nanofibres

“…Various mechanisms for the evolution of nanocubes and nanobers have been proposed, including dissolution-recrystallization and oriented growth. 9 In the case of low NaOH concentration, the growth rate is different in different directions producing plates and agglomerations. The increase of mineralizer concentration might hasten the kinetics of dissolution-recrystallization process.…”

“…In contrast, sintered BNT nanocubes have higher mechanical quality factor (Q m ) than that of nano-ber counterparts. 9 It is also reported that crystal morphology of the BNT nanostructures, as a template, controls the grain growth and density of ceramics. Ceramics sintered from BNT nanobers have a large grain size which facilitates domain switching and subsequently results in a signicant improvement of piezoelectric and ferroelectric properties.…”

“…8 It has been reported that different precursors and morphologies have a signicant effect on energy transition and mass of piezoelectric material aer the sintering process which consequently affects the electrical properties and density of sintered piezoelectric materials. 9,10 For example, sintered BNT nanobers have higher piezoelectric constant (d 33 ), planar electromechanical coupling factor (k p ) and remnant polarization (P r ) than sintered BNT nanocubes. In contrast, sintered BNT nanocubes have higher mechanical quality factor (Q m ) than that of nano-ber counterparts.…”

“…Ceramics sintered from BNT nanobers have a large grain size which facilitates domain switching and subsequently results in a signicant improvement of piezoelectric and ferroelectric properties. 9 The nanostructured materials present fascinating and applicable properties because of quantum size and specic shape effects. Particularly, one-dimensional (1D) lead-free ferroelectric materials including nanobers, nanotubes and nanoribbons are greatly desirable owing to their high surface to volume ratio, exceptional properties in energy harvesting, photocatalysis, electromechanical device and ferroelectric memories.…”

Hydrothermal Synthesis and Phase‐, Morphology‐Evolution Mechanism of Lead Titanate Nanostructures Assisted with Tetramethylammonium Hydroxide

“…[9,10] Due to the high temperature in calcination for getting pure crystallized PbTiO 3 perovskite, severe Pb loss and agglomeration always occur accompanying the formation of PbTiO 3 perovskite. [7,8,[19][20][21][22][23] Generally, under the effect of strong bases, such as potassium hydroxide and sodium hydroxide, PbTiO 3 perovskite cubic or tetragonal particles are obtained by hydrothermal reaction route. Among these methods, the hydrothermal technique is an aqueous-based precipitation route, which could control over the nucleation and crystal growth by tuning the hydrothermal reaction conditions, such as hydrothermal treatment temperature, time, starting precursors, mineralizer, feedstock concentration, as well as modifiers.…”