|About this Abstract
||Materials Science & Technology 2012
||Advances in Dielectric Materials and Electronic Devices
||Impedance Spectroscopic Investigation of CuO-Added Potassium Sodium Niobate Lead-Free Piezoelectric Ceramics
||Ebru Mensur-Alkoy, Ayse Berksoy-Yavuz
|On-Site Speaker (Planned)
Pure and 1mol% copper oxide added lead-free potassium sodium niobate - KNN (K<SUB>0.5</SUB>Na<SUB>0.5</SUB>NbO<SUB>3</SUB>) ceramics were prepared by solid state calcination method. Copper oxide was mainly used as a sintering aid. Microstructural analyses clearly showed that the copper oxide formed a secondary phase at the grain boundaries. Impedance spectroscopy was used as a tool to analyze electrical behavior of KNN ceramics as a function of frequency from 100 Hz to 10 MHz at various temperatures. The impedance studies proved that copper oxide led to the formation of a secondary grain boundary phase, as well as creation of highly mobile point defects. The relaxation time of copper added sample was less than that of pure KNN. This shorter time indicated a higher space charge mobility for copper oxide added sample. The thermal activation energy for relaxation of charge carriers (E<SUB>g</SUB>) was calculated as 0.73 eV for copper oxide added sample.