Influence of Li and La content on phase structures and electrical properties of K0.5Na0.5NbO3 lead-free piezoelectric ceramics
authors Rai, R; Rani, R; Sharma, S; Kholkin, AL
nationality International
journal JOURNAL OF ALLOYS AND COMPOUNDS
author keywords Lead-free piezoelectric ceramics; Phase structure; Stoichiometry; (K0.5Na0.5)LixLaxNbO3
keywords ELECTROMECHANICAL PROPERTIES; BEHAVIOR; NIOBATE
abstract Lead-free piezoceramics (K0.5Na0.5)(1-2x)LixLaxNbO3 (where x = 0.050, 0.055, 0.060, and 0.065) have been fabricated by a conventional sintering technique. The effect of Li and La doping on the phase structure and electrical properties of (K0.5Na0.5)(1-2x)LixLaxNbO3 ceramics was investigated. X-ray diffraction analysis showed that the ceramics possess a perovskite structure with orthorhombic symmetry. A small amount of second phase (K6Li4Nb10O30, similar to 3%) was present in KNLLN ceramics. Ferroelectric-paraelectric phase transition temperature decreases with increase in doping content. La-doping in the ceramics displayed a relative lower loss tangent (tan delta) from room temperature up to 350 degrees C. Detailed studies of dielectric and electrical properties indicate that the Curie temperature shifted to lower temperature with the increase in Li and La doping. Moreover, the dielectric maxima dropped down rapidly and the dielectric peaks became extremely broad. The weak dielectric properties for the samples of x = 0.065 can be ascribed to the formation of pseudo-cubic structures at high level of Li and La substitution. The AC conductivity increases with increase in temperature showing a negative temperature coefficient of resistance (NTCR) behavior. The low value of activation energy obtained for the ceramic samples could be attributed to the influence of electronic contribution to the conductivity. (C) 2013 Elsevier B.V. All rights reserved.
publisher ELSEVIER SCIENCE SA
issn 0925-8388
year published 2013
volume 577
beginning page 575
ending page 580
digital object identifier (doi) 10.1016/j.jallcom.2013.06.139
web of science category Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering
subject category Chemistry; Materials Science; Metallurgy & Metallurgical Engineering
unique article identifier WOS:000324082800095
  ciceco authors
  impact metrics
journal analysis (jcr 2019):
journal impact factor 4.65
5 year journal impact factor 4.082
category normalized journal impact factor percentile 77.703
dimensions (citation analysis):
altmetrics (social interaction):



 


Sponsors

1suponsers_list_ciceco.jpg