Investigation of Structural, Dielectric and Electrical Properties of Barium Titanate Ceramics Co-Doped with Bismuth and Yttrium

Bismuth and Yttrium co-doped Barium Titanate (BaTiO3) ceramics with the general formula (Ba1-xBiX) (YxTi1-x) O-3 (where x = 0.00, 0.01, 0.03, 0.05) have been synthesized at 1300 degrees C for 3 h by the standard solid-state reaction method. The prepared samples were characterized by X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and Impedance Analyzer. Temperature-dependent dielectric properties of the samples were also measured. The XRD result revealed perovskite structure for un-doped and co-doped BaTiO3 with tetragonal phase. However, with increasing doping concentration, a Pseudo cubic phase occurs also confirmed by the twin peaks (002) and (200) of XRD pattern. From SEM micrograph, submicron size particles were observed for all synthesized BaTiO3 samples and exhibit a narrow size distribution with quiet uniform morphology. The crystalline size for un-doped BaTiO3 found was 24.26 nm, the size decreases (minimum 19.59 nm for x = 0.03) for all compositions of co-doped BaTiO3. Dielectric constant values were apparently high and direct current (DC) resistivity follows a decreasing trend at higher doping concentration. The sample doped with x = 0.01 shows minimum DC resistivity and maximum dielectric constant among the samples investigated.