Investigation of the role of Sm, Na in ferroelectric, piezoelectric and conduction behaviour of Strontium Bismuth Titanate ceramics

The manuscript presents a systematic study of ferroelectric, piezoelectric and conduction behaviour of Sm, Na substituted Strontium Bismuth Titanate ceramics, prepared by solid-state reaction method. The structural analysis of Bismuth layer structured ferroelectrics (BLSF) of Sr1-2xSmxNaxBi4Ti4O15 (SSNBTi) ceramics was done by X-ray Diffraction technique and it showed single-phase formation and peak shifting towards the higher angles. Scanning Electron Microscopy confirmed orthorhombic sheet-like grain structure with random orientation of grains. P-E study and Piezoelectric studies were done at room temperature (RT); improved remnant polarization (P-r = 1.95 mu C/cm(2)), Piezoelectric charge coefficient (d(33) = 21.1 pC/N) and electromechanical coupling factor (k(p) = 0.71) were achieved by substitution of Sm, Na (x = 0.4) in Sr of SBTi ceramics. The AC conductivity was studied from RT to 600 degrees C in the frequency range of 1 kHz-100 kHz. The trends shown by Activation energies obtained from Arrhenius plots suggests that the mechanism of conduction is through short-range oxygen vacancies hopping. The combination of improved ferroelectric properties and high piezoelectric constant (k(p) = 0.71) make the SSNBTi ceramics suitable for a wide range of sensor, actuator, and transducer applications.