Structural, Electrical, and Optical Behavior of Strontium Bismuth Titanate Ceramic

Abstract

In this report, we present the structural, electrical, and optical study of layer-structured SrBi4Ti4O15 (SBT) ceramic prepared by solid-state reaction route. The X-ray diffraction and Rietveld refinement studies show a single-phase orthorhombic structure with space group A(21)am. The scanning electron micrograph shows plate-like grains. The various Raman peaks originated due to the TiO6 octahedron confirm the orthorhombic structure. The temperature-dependent dielectric study shows a normal ferroelectric phase transition with a transition temperature at 813 K (540 A degrees C). Impedance studies show a non-Debye-type relaxation and relaxation frequency shift to higher side with increase in temperature. The Nyquist plot shows overlapping semicircles which results the existence of both for grain and grain boundary effect in SBT ceramic. The frequency-dependent AC conductivity at different temperatures indicates that the conduction process is thermally activated and the spectra follow the universal power law. The variation of DC conductivity confirms that the SBT ceramic exhibits negative temperature coefficient of resistance behavior. The Ferroelectric behavior is studied by hysteresis loop. The optical band gap is found to be 2.93 eV from the UV-Visible spectroscopy study. The room-temperature photoluminescence study shows a strong red emission.