Structural and Dielectric Properties of Ba-Doped BNT Ceramics

Abstract

In this study, lead-free Ba-doped ((Bi(0.5)Na0.5)TiO3 ceramics were synthesized by the conventional solid-state reaction method and characterized by X-ray diffraction technique, which indicates the pure crystalline nature of ceramics with ABO3 symmetry. The splitting in the peaks reveals that the ceramics with x = 0.10 and 0.30 are well in Morphotrophic Phase Boundary where rhombohedral and tetragonal phases co-exist. The scanning electron microscope images show that the average grain size of the ceramics increases with an increase in the Ba concentration. Dielectric properties of pure and Ba-doped ((Bi(0.5)Na0.5)TiO3ceramics measured by LCR meter in the frequency range of 1 k Hz – 1 M Hz shows the decrease in the value of dielectric constant with an increase in frequency. εmax = 5563 was obtained at x = 0.30 with TC = 300 °C at the frequency of 1 k Hz, whereas σ (f) curves were found to be merging at a high value of frequency and temperature regions.

Impedance Study of Temperature-Stable Relaxor Dielectrics in the System of BCT-BMT Ceramics

“…Also, the lattice parameters and crystal volume size are estimated and are displayed in Table . Rietveld refinement structural parameters of BCT-BMT dielectrics are summarized via the FullProof suite (where Pm 4 m and Pm 3̅ m space groups stand for tetragonal and pseudocubic symmetry, respectively). − …”

“…Rietveld refinement structural parameters of BCT-BMT dielectrics are summarized via the FullProof suite (where Pm 4 m and Pm 3̅ m space groups stand for tetragonal and pseudocubic symmetry, respectively). 14 − 17 …”

“…The crystallite size and lattice strain effect in the prepared ceramic were estimated by adopting the Williamson–Hall (W–H) method. 14 − 16 where k = 1.5405, λ = 0.89 Å, β = full width at half maxima (FWHM), θ = half of the diffraction angle, and t = crystallite size of the sample. The relation shows a straight line, in which η is the gradient (slope) of the line and is the y-intercept.…”