Dielectric properties of Ga₂O₃-doped barium iron niobate ceramics

Abstract

Ga-doped BaFe 0.5 Nb 0.5 O 3 (Ba(Fe 1-x Ga x ) 0.5 Nb 0.5 O 3 ) ceramics were fabricated and their properties were investigated. All ceramics showed perovskite structure with cubic symmetry and the solubility of Ga in BFN ceramics had a limit at x ¼ 0.2. Examination of the dielectric spectra indicated that all ceramic samples presented high dielectric constants that were frequency dependent. The x ¼ 0.2 ceramic showed a very high dielectric constant (e r > 240 000 at 1 kHz) while the x ¼ 0.4 sample exhibited high thermal stability of dielectric constant with low loss tangent from room temperature (RT) to 100 8C with e r > 28 000 (at 1 kHz) when compared to other samples. By using a complex impedance analysis technique, bulk grain, grain boundary, and electrode response were found to affect the dielectric behavior that could be related to the Maxwell-Wagner polarization mechanism ß

Effects of Electrode on Dielectric Properties of Barium Iron Niobate Ceramics Doped with Gallium Oxide

“…[15]. Furthermore, the result was confirmed by X-ray diffraction investigation [12]. The dielectric tenability characteristic was determined from the measurement of dielectric constant under applied electric field.…”

“…A-site doping using La and Na as dopants, on the dielectric properties of BFN have also been studied [10,11]. Our previous work showed that the Ga doped BFN showed better dielectric properties as compared to unmodified BFN [12]. In the present work, we report a further study into the effect of type of electrode on the dielectric properties of the Ga doped BFN.…”

Effect of barium iron tantalate incorporation on mechanical, electrical, and magnetocapacitance properties of modified bismuth sodium potassium titanate ceramics

“…This may be due to the change in resistance at bulk grain and grain boundary of the samples after the additive was added. These resistances can be changed under the applied magnetic field [9,32], as a result in a change of r value [33].…”

The Effects of Sintering Temperature on the Dielectric Properties of Sr(FeNb)_0.5O₃ Doped with Ba(Zr_0.25Ti_0.75)O₃

“…The co-existence of Fe 2+ and Fe 3+ ions can give rise to the Fe 2+ /Fe 3+ polaron hopping conduction mechanism. Further, the Fe 2+ concentration is known to be sensitive to temperature, and have increases with increasing temperature [13]. After adding BZT an heterogeneous conduction may have occurred [13] due to BZT and SFN having a large difference of conduction which alter bulk grain and grain boundary characteristics.…”

“…Further, the Fe 2+ concentration is known to be sensitive to temperature, and have increases with increasing temperature [13]. After adding BZT an heterogeneous conduction may have occurred [13] due to BZT and SFN having a large difference of conduction which alter bulk grain and grain boundary characteristics. This can produce the Maxwell Wagner polarization mechanism in the sample and result in the very high dielectric constants.…”