Influence of tungsten doping on dielectric, electrical and ferroelectric behavior of BaBi4Ti4O15 ceramics

The effect of tungsten (W6+) doping on modification of the structure, dielectric, ferroelectric and electrical properties of BaBi4Ti4-xWxO15 (BBTWx, x = 0, 0.03, 0.05 and 0.07) was investigated. The ceramic samples were synthesized by the conventional solid state reaction method. XRD data indicated the formation of single-phase layered crystalline structure that confirmed orthorhombic structure type of all compositions with space group A21am. SEM micrographs suggest that the grain size slightly decreases with W doping. The temperature dependent dielectric study revealed that the dielectric constant decreases with W doping while transition temperature slightly increases. Influence of tungsten on relaxor behavior and diffuseness of phase transition is also discussed. Effect of W doping on the dielectric and electrical properties were investigated in terms of ion doping and defect mechanism. The ferroelectric properties were studied by P-E hysteresis loop and it was observed that the remanent polarization increases with a small level of W doping.