Doping effects of Li-Sb content on the structure and electrical properties of [(Na 0.5K 0.5) 1 - X(Li) x(Sb) x(Nb) 1 - xO 3] lead-free piezoelectric ceramics

Abstract

Ceramic samples of [Na 0.5K 0.5] 1 - x(Li) x(Sb) x(Nb) 1 - xO 3 (NKNLS) (x = 0.04-0.06) were prepared by high temperature solid-state reaction method. X-ray diffraction analysis of the powder samples suggests the formation of a single-phase material with transformation from orthorhombic to tetragonal crystal structure with increase in Sb content. Dielectric studies show a diffuse phase transition about 100 °C and another phase ferroelectric-paraelectric transition at 330 °C. Polarization vs. electric field (P-E) hysteresis studies show maximum remanent polarization (Pr ∼ 0.66 C m -2) for composition x = 0.05. AC conductivity in the compound increases with increase in temperature which may be attributed due to oxygen vacancies and show negative temperature coefficient of resistance (NTCR) effect. © 2011 Elsevier Ltd. All rights reserved.