Charge correlation of ferroelectric and piezoelectric properties of (1 − x)(Na0.5Bi0.5)TiO3–xBaTiO3 lead-free ceramic solid solution

• Published in: Journal of materials science. Materials in electronics Vol. 28; no. 13; pp. 9950 - 9963
• Main Authors: Sasikumar, S., Saravanan, R., Saravanakumar, S., Aravinth, K.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.07.2017; Springer Nature B.V
• Subjects: Ceramic powders; Characterization and Evaluation of Materials; Chemistry and Materials Science; Diffraction; Diffraction patterns; Ferroelectric materials; Ferroelectricity; Lead free; Materials Science; Optical and Electronic Materials; Piezoelectricity; X-rays; Maximum Entropy Method; Piezoelectric Property; Charge Density Distribution; BaTiO3; Morphotropic Phase Boundary
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-017-6753-5

Single phased lead-free (1 −  x )(Na 0.5 Bi 0.5 )TiO 3 – x BaTiO 3 ( x  = 0.00, 0.04, 0.08 and 0.12) ((1 −  x )NBT– x BT) ceramics were synthesized by the solid-state reaction method. The powder X-ray diffraction patterns and profile refinements revealed that, for 0.04 <  x  < 0.08, the prepared ceramics have been crystallized in morphotropic phase boundary between rhombohedral to tetragonal structures. The charge distribution and bonding behaviour in (1 −  x )NBT– x BT unit cell were completely analyzed through charge density distribution studies. UV–visible analysis reveals that, the optical band gap energy of the solid solution increases with addition of BaTiO 3 content. The surface morphology and elemental compositions for the sintered powders were analyzed through scanning electron microscopy and energy dispersive X-ray studies. Electrical measurements on the solid solutions showed that the maximum values of the dielectric constant, the remnant polarization and the piezoelectric coefficient are reached at near ( x  = 0.08) the morphotropic phase boundary ( ε  = 4070 at 100 kHz; P r = 18.92 µC/cm 2 ; d 33  = 122 pC/N). Thus, the (1 −  x )NBT– x BT system is expected to be a promising candidate for lead-free piezoelectric material.