Dielectric Properties of Bi₄Ti₃O₁₂ below the Curie Temperature

Abstract

The dielectric permittivity, optical transmission spectrum and temperature dependence of resistance were investigated in single crystals of Bi4Ti3O12 and BaBi4Ti4O15. It is found that the dielectric anomalies previously reported below the Curie temperature are due electron space charges of inhomogeneous distribution in the material and near the non-ohmic electrodes.

B-site Multi-element Doping Effect on Electrical Property of Bismuth Titanate Ceramics

“…It is well known that the intrinsic electronic conductivity activation energy is equal to half of the energy of the band gap (E g ). The reported value for the band gap is 3.3 eV for Bi 4 Ti 3 O 12 ceramics (Ehara, 1981) which is in close agreement with that of the present results (1.5 eV). It is interesting to note that the values for activation energy of dc conduction and electrical relaxation (Fig.…”

The effect of Nd substitution on the electrical properties of Bi3NbTiO9 Aurivillius phase ceramics

“…All compositions ͑x =0-1.0͒ are ferroelectrics, which was evidenced by their ferroelectric switching and piezoelectric properties. The piezoelectric coefficient d 33 and electrical resistivities of BNTO ceramics were greatly improved by Nd doping. The dc conduction of BNNT− x at low Nd doping contents ͑x Յ 0.2͒ above 400°C is related to an extrinsic p-type mechanism.…”

“…The similarity of the band gap is due to the common TiO 6 octahedra. 33 The combination of high d 33 values, high resistivities, and high T C points ͑Ͼ700°C͒ suggests that the compositions with x Յ 0.6 could be good candidates for high-temperature piezoelectric application.…”

“…The Bi 3−x Nd x NbTiO 9 ceramics exhibited a sharp ferroelectric-paraelectric phase transition at small x values ͑x Յ 0.6͒, whereas a diffuse phase transition was observed at higher x values ͑x Ն 0.8͒. Both the piezoelectric constant d 33 and the dc electrical resistivity of Bi 3 NbTiO 9 ceramics were greatly enhanced by Nd substitution on the A sites. The improved properties can be attributed to the fact that Nd substitution depressed the generation of oxygen vacancies.…”

“…The improved properties can be attributed to the fact that Nd substitution depressed the generation of oxygen vacancies. A combination of high d 33 values, high resistivity, and high T C points ͑Ͼ700°C͒ suggests that the Bi 3−x Nd x NbTiO 9 ceramics with x Յ 0.6 could be good candidates for high-temperature piezoelectric applications. © 2009 American Institute of Physics.…”