Ferroelectric and Piezoelectric Properties of Na_1−xBa_xNb_1−xTi_xO₃ Ceramics

Abstract

Piezoelectric ceramics Na1−xBaxNb1−xTixO3 with low BaTiO3 concentrations x have been prepared by the solid‐state reaction method, and their ferroelectric and piezoelectric properties have been studied. The ceramics are classic ferroelectrics when x≤0.10, and the ferroelectric–paraelectric phase transition becomes diffusive when x≥0.15. A low doping level of BaTiO3 changes the NaNbO3 ceramics from antiferroelectric to ferroelectric. With the increase in BaTiO3 doping level, the Curie temperature of ceramics decreases linearly and the remnant polarization and coercive field also decrease, while their dielectric constant increases. Na0.9Ba0.1Nb0.9Ti0.1O3 ceramics show the largest piezoelectric constant d33 (147 pC/N) and good sinterability, suggesting that it is a good candidate for lead‐free piezoelectric ceramics.

Enhancing dielectric permittivity for energy-storage devices through tricritical phenomenon

“…The optimal permittivity has been found on the multi-phase point, which will be verified as a tricritical point in the later part of this paper. We then depicted the BTS- x (x = 10.5, 12, 13) close to tricritical point (nominated as tricritical ferroelectrics) on the E b - ε r plot and compared it with a series of other energy storage material systems1718192021222324252627 in Fig. 1(b).…”

“…( b ) The locations for a series of materials categories on the dielectric permittivity( ε r )-breakdown strength ( E b ) plot (reproduced from refs 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23), and the tricritical BTS materials at high permittivity region may result in a large energy storage properties at low electric field. ( c ) The polarization(P)-electric field (E) hysteresis loops for tricritical-point-nearby BTS- x and the other ferroelectric materials at low electric field region with E  < 10 kV/cm.…”

Synthesis of a sodium niobate-based lead-free piezoelectric ceramic using a submicron-sized NaNbO<inf>3</inf> powder

“…Sodium niobate NaNbO 3 (NN) is a well-known anti-ferroelectric material, and some NN-based perovskite solid solutions, such as (1-x)NaNbO 3 -xABO 3 with a small x value exhibit piezoelectric and ferroelectric properties above room temperature. Also, they have Curie temperatures higher than BaTiO 3 for BaTiO 3 concentration x<0.15 [1][2][3][4]. The NaNbO 3 -BaTiO 3 solid solution system [(Na,Ba)(Nb,Ti)O 3 ] has been widely investigated because BaTiO 3 and NaNbO 3 are known ferro-and anti-ferroelectric materials, respectively, and relaxor behavior has been observed for this system [1,5,6].…”

Effects of BaTiO3Content and Mn Doping on Ferroelectric Properties of NaNbO3–BaTiO3Thin Films Prepared by Chemical Solution Deposition

“…[2][3][4][5][6][7] Recently, ferroelectric NaNbO 3 -BaTiO 3 (NN-BT) solid solution has been reported as a potential candidate material, and has shown good ferroelectric and piezoelectric properties. 8) In general, for the preparation of alkali niobate ceramics, it is difficult to control the chemical composition, because volatilization of the alkali metal element easily occurs during heat treatment at high temperatures. As for NN-BT, although it contains sodium as a major constituent, it does not contain volatile potassium.…”

“…Moreover, the reported Curie temperature (T c ) and piezoelectric coefficient (d 33 ) are approximately 230 C and 150 pC/N, respectively, for the composition of 0.9NaNbO 3 -0.1BaTiO 3 , which are relatively high values compared with those of other lead-free piezoelectric materials. 8) On the other hand, to apply ferroelectric materials to electronic thin-film device applications, such as piezoelectric microelectromechanical system (MEMS) devices, thin-film processing has become increasingly important. Among several thin-film processing methods, chemical solution deposition (CSD) is a representative process with several advantages, such as high homogeneity, low-temperature fabrication, precise control of chemical composition, and low equipment costs.…”