Electrical, electromechanical and structural studies of lead potassium samarium niobate ceramics

• Published in: Journal of alloys and compounds 2008-09, Vol.464 (1), p.497-507
• Main Authors: Rao, K. Sambasiva, Murali Krishna, P., Madhava Prasad, D., Lee, Joon-Hyung, Kim, Jin-Soo
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric loss and relaxation; Dielectric properties; Dielectric properties of solids and liquids; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Electrical properties; Exact sciences and technology; Physics; Piezoelectric; Piezoelectricity and electromechanical effects; TB structure
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2007.10.023

Dielectric spectroscopy has been applied to investigate the electrical properties of tungsten bronze ferroelectric ceramics of Pb 0.77K 0.115Sm 0.115Nb 2O 6 (Sm:PKN) over a wide frequency (45 Hz to 5 MHz) and temperature (35–600 °C) range. XRD analysis showed the lattice parameters, a = 17.731 Å, b = 18.035 Å and c = 3.843 Å. Determined the piezoelectric constants, K p = 18%, K t = 21%, d 33 = 68, and quality factor ( Q m) = 38, reveals the material may be useful for transducer applications. Similar peak positions of normalized electrical modulus and impedance plots indicate the long range conductivity in Sm:PKN. Cole–Cole plots observed to be non-Debye type with polydispersive in nature. Determined the coefficient A( T) = { a( T) S/ L}, the exponent n( T) fitted the Jonscher's dielectric dispersion relations for ɛ I with experimental data. Parameters n( T) and A( T) showed an anomaly at the vicinity of T C, respectively. dc and ac conduction activation energies are estimated from Arrhenius plots. Compared the results from different techniques, and discussed the conduction mechanism in the material.