Effect of cerium addition on the microstructure, electrical and relaxor behavior of Sr0.5Ba0.5Nb2O6 ceramics

• Sr0.5-3y/2Ba0.5CeyNb2O6 synthesized using solid-state reaction method.
• Cerium dopant improved the overall properties of SBN.
• Dopant incorporation lowers the phase transition temperature, Tm.
• 3% Ce dopant exhibits best functional properties among the rest of the composition.
• The Pr of 3%Ce-doped SBN is 58.6 μC/cm2 and ε’ ≈ 8000 (10 kHz) at room temperature.

Sr0.5Ba0.5Nb2O6 (SBN50) ceramic doped with different concentrations of Cerium (Ce) according to the stoichiometry formulation of Sr0.5-3y/2Ba0.5CeyNb2O6 (Ce-SBN) with y = 0, 0.01, 0.02, 0.03, 0.04 and 0.05 was prepared using the conventional solid state reaction method. The morphology, structure, and electrical properties of the samples were studied using field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), ferroelectric and dielectric spectroscopy, respectively. The FESEM images reveal a strong influence of cerium on the SBN microstructure. The X-ray diffraction patterns show that all compositions of SBN ceramic exhibit tetragonal tungsten bronze structure. As the dopant concentration, y increased, both unit cell volume and axial ratio c/a decreased gradually. In addition, dopant incorporation lowers the phase transition temperature, Tm. As a result, all practical parameters are sufficiently increased, i.e. the dielectric constant and remnant polarization. SBN50 doped with a 3% Ce sample is most attractive for practical applications due to its high remnant polarization, Pr = 58.6 μC/cm2 and dielectric constant, ε’ ≈ 8000 (10 kHz) at room temperature, respectively.