Structural, dielectric and energy storage properties of Neodymium niobate with tetragonal tungsten bronze structure

Abstract : The present work reports the effect of Nd3+ substitution on the structural, dielectric and energy storage properties of the polycrystalline Ba2NaNb5O15(BNN) ceramics. The ferroelectric lead-free Ba2Na1-xNdx/3Nb5O15 ceramics were prepared by conventional solid-state reaction technique. The room temperature X-ray study and Raman spectroscopy investigations have allowed evidencing the stabilization of a tetragonal tungsten bronze structure with P4bm space group for all the studied compounds. Dielectric study carried out on the prepared ceramics has permitted to determine the temperature of phase transitions (Tc). It was found that the dielectric constant increased with increasing the amount of Nd in BNN matrix. Room temperature energy storage property was determined using P-E hysteresis loops. The optimum discharge density was found for the composition x = 0.7 with Wrec = 18.1 mJ cm-3) at 1 Hz. Finally, the dynamic of phase transition was approached using thermal Raman spectroscopy investigations.