Concomitant structural and ferroelectric properties of Sr2Bi4Ti5O18 ceramics sintered with perovskite

Abstract

Lead free piezoelectric ceramics with the composition(1-x)Sr ☆ e þ x [(K 0.41 Na 0.53 Li 0.06 )(Nb 0.89 Sb 0.06 Ta 0.05 )O ] (where x ¼ 0, 0.05, 0.10, 0.15 and 0.20) were synthesized using the pre-reacted Sr 2 Bi 4 Ti 5 O 18 (SBT) and [(K 3 0.41 Na 0.53 Li 0.06 )(Nb 0.89 Sb 0.06 Ta 0.05 )O ](KNLNST) powders via solid-state reaction carried out at 1130

3 C. Based on X-ray diffraction studies it was confirmed that only less than 0.15 mol of KNLST was soluble in the SBT phase. Raman spectra analyses for these samples revealed that A and B site cations from KNLNST perovskite phase were found to occupy A and B site cations of SBT. There was an increase in the grain size with the increase in x and grains with plate-like morphology were seen in these samples when observed through a scanning electron microscope (SEM). The measured values of relative permittivity (rational electric permittivity) (300 at 1 MHz), dielectric loss (0.013 at 1 MHz), and maximum polarization (5.95 μC/cm ) for the samples with the composition x ¼ 0.2 were found to be superior to that of undoped SBT. The decrease in Curie temperature with the increase in x for all the samples under study was confirmed through temperaturedependent dielectric measurements.