Impedance characteristics and PTCR effect in lead free BaTi1-xSnxO3 piezoceramics. (October 2018)

• Record Type: Journal Article
• Authors: Kola, Lakshmi; Swain, Atal Bihari; Rath, Martando; Rao, M. S. Ramachandra; Murugavel, P.
• Is Part Of: Materials research bulletin. Volume 106(2018)
• Page Start: 371
• Page End: 378
• Publication Date: 2018-10
• Subjects: Piezoelectric -- Impedance -- Relaxation -- Ac conductivity -- PTCR; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2018.06.021
• Languages: English
• ISSNs: 0025-5408

Abstract

Graphical abstract: Highlights: The maximum d 33 = 296 pC/N and P r = 6.92 μC/cm 2 is observed for x = 0.08. Nyquist plots reveal non-Debye type relaxation behavior of the samples. Impedance studies indicate a possible correlation between d 33 and microstructure. Positive temperature coefficient of resistance (PTCR) is seen just above T C . Abstract: BaTi1- x Sn x O3 of compositions x = 0.07, 0.08, 0.09, 0.10 and 0.11 are synthesized to study their piezoelectric and impedance characteristics. The studies revealed that the composition x = 0.08 exhibits the maximum piezoelectric coefficient ( d 33 = 296 pC/N) and remnant polarization ( P r = 6.92 μC/cm 2 ) values. The impedance analysis showed that the depressed semi-circular arc observed in the Nyquist's plots gave evidence for the existence of non-Debye type relaxation behavior in the compounds. The impedance studies suggested a possible correlation between the d 33 and microstructural properties. The activation energies extracted from ac conductivity plots strongly indicate the existence of defect dipole assisted conductivity mechanism in the samples. Notably, the samples displayed positive temperature coefficient of resistance (PTCR) just above their ferroelectric transition. The frequency dependent ac conductivity follows the Jonscher's universal power law. The dominant conduction mechanism in the samples is determined to be the small polaron hopping mechanism.