Relaxor behavior of PbxBi4Ti3+xO12+3x (x=2,3) Aurivillius ceramics

Abstract

The relaxor response of the PbxBi4Ti3+xO12+3x (x=2,3) Aurivillius ceramics is reported. The relaxor behavior appears with an increase of the symmetry in the ab plane of the structure and a decrease of the transition temperature. By the application of a bias field on nonpoled samples, it is possible to induce the piezoelectric response. The piezoelectric coefficient in the planar mode of −72 pC/N was measured at 210 °C for Pb2Bi4Ti5O18 ceramic disks. These results represent a step in the search of high-temperature piezoelectric ceramics.

Aurivillius phases of PbBi4Ti4O15 doped with Mn3+ synthesized by molten salt technique: Structure, dielectric, and magnetic properties

“…The broad peak, the ferroelectric ordering temperature (T c ), is attributed to the disorder of Pb and Bi atoms in the Bi 2 O 2 layers and in the perovskite layers as described for PbBi 2 Nb 2 O 9 [30]. The (T c ) peaks of Pb 1 À x Bi 4 þ x Ti 4 À x Mn x O 15 resemble the observations by Fernandez et al [3] (808 K) and are slightly lower than the value reported by Subbarao [2] (843 K) and Ikezaki et al [29] (823 K) both for composition of PbBi 4 Ti 4 O 15 . However, the sample x ¼0.6 exhibits a peak at higher temperature (850 K).…”

“…It can be noted that the dipole moment from Ti(1)O 6 displacements is close to zero for xZ0.4, indicating a small contribution from this layer. In the Aurivillius phases with Pb x Bi 4 Ti 3 þ x O 12 þ 3x series, the T c is found to increase as the number of perovskite layer decreases [2,3]. Presumably increasing T c in Pb 1 À x Bi 4 þ x Ti 4 À x Mn x O 15 can be caused by a decrease of the contribution of the inner Ti(1)O 6 octahedra and a larger contribution of more distorted outer Ti(2)O 6 octahedra.…”

“…Generally, the A-site is occupied by mono-, di-or tri-valent cations that have dodecahedral coordination, whereas the B-site is occupied by a transition element with octahedral coordination, n is an integer representing the number of sheets of corner-sharing BO 6 octahedra forming the ABO 3 -type perovskite blocks. Most of these phases have been known as ferroelectric materials with high Curie temperatures, T c , such as Bi 4 Ti 3 O 12 (948 K), PbBi 4 Ti 4 O 15 (843 K), and Pb 2 Bi 4 Ti 5 O 18 (583 K) [2,3]. The perovskite layer is considered to be responsible for the ferroelectricity due to the presence of d 0 transition cation such as Ti 4 þ .…”

Dielectric and piezoelectric properties of Na0.5Bi4.5Ti4O15–(x−1)Na0.5Bi0.5TiO3 composite ceramics

“…Since its discovery by Aurivillius in 1949 [4], Bi 4 Ti 3 O 12 has attracted considerable attention due to its high Curie temperature of about 675 • C [5][6][7]. Many BLSF with m = 4 or 5 can also be derived from Bi 4 [8][9][10][11][12][13][14]. Recently, structural investigations on the Bi 4 Ti 3 O 12 + xNa 0.5 Bi 0.5 TiO 3 system have revealed that the bismuth layer-structured Na 0.5 Bi 4.5 Ti 4 O 15 phase and the perovskite Na 0.5 Bi 0.5 TiO 3 phase are prone to reject each other in their solid solution [15,16].…”

Structural stability and cation disorder in Aurivillius phases

“…In addition to making quantitative predictions for cation exchanges in phases of the (Bi 2Àx Pb x O 2 )(Pb y Bi 1Ày ) nÀ1 B n O 3n+1 type, the model can be used to explain qualitatively the inexistence of phases with a high value of n. In the isoestructural series as Pb nÀ3 Bi 4 Ti n O 3n+3 , for example, only phases with n 7 are reported [3,34]. In these materials, the cation exchange should contribute to the phase stability.…”