Relaxation and conduction mechanism of BNT-KNN ceramics by impedance study. (10th September 2017)

• Record Type: Journal Article
• Authors: Chandrasekhar, M.; Kumar, P.; Prakash, C.; Kumar, Anil
• Is Part Of: Ferroelectrics. Volume 517(2017)
• Page Start: 58
• Page End: 65
• Publication Date: 2017-09-10
• Subjects: Relaxation -- impedance -- modulus -- conductivity -- activation energy; Ferroelectricity -- Periodicals; Ferroelectric crystals -- Periodicals; 537
• DOI: 10.1080/00150193.2017.1369835
• Languages: English
• ISSNs: 0015-0193

Abstract

ABSTRACT: Impedance spectra of 0.93BNT-0.07KNN revealed positive and negative temperature coefficient of resistance behaviour up to 400 °C and above 400 °C . With the increase of temperature, decreased radii and displaced centres of semicircles from the real axis of impedance Cole-Cole plots suggested non-Debye type relaxation mechanism. Three dielectric relaxation regions: within (i) grain, (ii) grain- grain boundary and (iii) grain boundary were prominent in lower, middle and high temperature regions, respectively. The activation energy ranging from ∼0.79 to 1.2 eV, suggested that the conduction carriers were cation and cation, oxygen vacancies in lower and higher temperature regions, respectively.