Alkoy, Ebru MensurBerksoy-Yavuz, Ayse2024-07-122024-07-1220120885-30101525-895510.1109/TUFFC.2012.24382-s2.0-84869458995https://dx.doi.org/10.1109/TUFFC.2012.2438https://hdl.handle.net/20.500.12415/8039Pure and 1 mol% CuO-added lead-free potassium sodium niobate K0.5Na0.5NbO3 (KNN) ceramics were prepared by the conventional solid-state calcination method. Copper oxide was mainly used as a sintering aid in the KNN structure. Microstructural analyses clearly showed that the CuO formed a secondary phase at the grain boundaries. Impedance spectroscopy was used as a tool to analyze the electrical behavior of KNN ceramics as a function of frequency from 100 Hz to 10 MHz at various temperatures. The impedance studies proved that CuO 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 samples was less than that of pure KNN. This shorter time indicated a higher space charge mobility for CuO-added samples. The thermal activation energy for relaxation of charge carriers (E-g) was calculated as 0.73 eV for CuO-added samples.eninfo:eu-repo/semantics/closedAccessArticle21281023143562Q1212159WOS:000310896600001Q1