High permittivity (1−x)Bi_1/2Na_1/2TiO₃‐xPbMg_1/3Nb_2/3O₃ ceramics for high‐temperature‐stable capacitors

Abstract

(1−x)Bi1/2Na1/2TiO3‐xPbMg1/3Nb2/3O3[(1−x)BNT‐xPMN] ceramics have been fabricated via a conventional solid‐state method for compositions x ≤ 0.3. The microstructure, phase structure, ferroelectric, and dielectric properties of ceramics were systematically studied as high‐temperature capacitor materials. XRD pattern certified perovskite phase with no secondary phase in all compositions. As PMN concentration increased, the phase of (1−x)BNT‐xPMN ceramics transformed from ferroelectric to relaxor gradually at room temperature, with prominent enhancement of dielectric temperature stability. For the composition x = 0.2, the temperature coefficient of capacitance (TCC) was <15% in a wide temperature range from 56 to 350°C with high relative permittivity (>3300) and low dielectric loss (<0.02) at 150°C, which indicated promising future for (1−x)BNT‐xPMN system as high‐temperature stable capacitor materials.

Enhanced High Temperature Stability of BNT-BKT-CBTZ Lead-Free Dielectrics

“…Two types of dielectric anomalies peaks are observed at ɛ -T plots, corresponding to a low-temperature shoulder (T s ) and a high-temperature broad maximum (T m ) similar to other BNT-based ceramics. [34][35][36] The origin of two anomalies both are associated with the polar nanoregions (PNRs). T s is related to the relaxor characteristic that may be attributed to the thermal evolution of low-temperature PNRs and T m is ascribed to the mixture of the rhombohedral (R3c) and tetragonal (P4bm) structure in high-temperature PNRs.…”

High electrostrictive properties and energy storage performances with excellent thermal stability in Nb-doped Bi0.5Na0.5TiO3-based ceramics

“…Furthermore, with the increasing Nb content, the dielectric constant maximum 3 m decreases sharply, getting closer to the dielectric constant value at T s and resulting in the formation of dielectric plateau in a wide temperature range. 19 The temperature independence of the dielectric properties is closely related to the thermal stability of electric behaviors. 19 domain back switching during loading electric eld.…”

“…19 The temperature independence of the dielectric properties is closely related to the thermal stability of electric behaviors. 19 domain back switching during loading electric eld. 20 With the increase of Nb content, it could be clearly observed that the S neg has been declining to 0 while the S pos rises signicantly.…”

Dielectric property and energy storage performance enhancement for iron niobium based tungsten bronze ceramic

“…[6][7][8][9] At the same time, the change of dielectric property with temperature is normally gentle for relaxor, which is conducive to obtaining relative stable dielectric permittivity, ferroelectric polarization and energy storage density in a wide temperature range. 10,11 In addition, the dynamic domain switching barrier of nano polar micro regions in relaxor ferroelectrics is lower, and the exibility of domain wall movement can inhibit the pinning of defects, which all greatly improve the fatigue resistance and increase the service life of the materials. 6 Tungsten bronze is one of the most important class of ferroelectrics, the cell structure is shown in the inset of Fig.…”