Investigations on structure, dielectric and ferroelectric properties of SrBi₂Ta₂O₉ ceramic via A-site defect engineering

ABSTRACT

Yttrium-modified bismuth-layered ferroelectric SrBi₂Ta₂O₉ (SBT) with general formula SrBi_2-xY_3x/4Ta₂O₉ (where x = 0.00, 0.025, 0.05, 0.075 and 0.10) are prepared by mixed oxide route. The structural, dielectric, ferroelectric and conductivity behavior of the above compounds for each composition of Y is discussed. The formation of monophase materials is noted from the X-ray diffraction pattern. The structure of the grains is studied using Scanning electron microscopy. The variation of the dielectric permittivity with temperature at some particular frequencies manifests a diffuse order phase transition with reduced T_c (ferroelectric transition temperature) and ϵ_r (relative permittivity) with respect to higher concentration of Y. The ferroelectric properties in the materials are confirmed using hysteresis (P-E) loops. The remnant polarization of the materials is found to increase with the addition of Y while the coercive field follows the reverse trend.

KEYWORDS:

• Bismuth layered structure
• dielectric parameters
• hysteresis curve
• ferroelectric

Disclosure statement

No potential conflict of interest was reported by the author(s).