Microstructure And Dielectric Relaxation Of BT And ST Doped Ba(Fe0.5Nb0.5)O3 ceramics For Sensor Applications

Recently a new wave of interest has risen on complex perovskite structure due to their wide use in fabrication of multilayer ceramic capacitors, electrostrictive actuators, and electromechanical transducers. The polycrystalline ceramics of Ba(Fe0.5Nb0.5)O3 (BFN) and its solid solutions 0.89Ba(Fe0.5Nb0.5)O3-0.11BaTiO3 (BFN-BT11) and 0.89Ba(Fe0.5Nb0.5)O3-0.11SrTiO3 (BFN-ST11) were fabricated by a solid-state reaction Method. Processing parameters such as calcination temperature, sintering temperature and sintering durations were optimized to get best dielectric properties. It was found that the above ceramics sintered at 1250°C for 6 hours exhibited maximum density and uniform microstructure. X-ray diffraction studies of the compound showed the formation of single-phase monoclinic crystal structure at room temperature. Surface morphology of the compounds was studied by Scanning electron microscope (SEM). The effects of BaTiO3 and SrTiO3 substitution on the structure and on the electrical