2017 : Analysis of the crystal structure and electrical properties of Li-doped (K, Na)NbO3 prepared by solid state reaction

Prof. Dr. Suasmoro


Abstract

(K0.5Na0.5)NbO3 (KNN) and (K0.5Na0.4Li0.1)NbO3 (KNLN) ceramic were successfully prepared by solid state reaction method. Single phase KNN was obtained from calcined of mixed powders K2CO3, Na2CO3 and Nb2O5 at 700°C/2h and sintered of KNN pellets at 1125°C/4h. Similar with KNN, single phase KNLN was obtained from calcined of mixed powders K2CO3, Na2CO3, Li2CO3 and Nb2O5 at 750°C/2h and sintered of KNLN pellets at 1100°C/2h. The result of XRD pattern of KNN before and after Li-doped were investigated. By using Rietveld refinement method, it was known that the Li-doped makes KNN crystal structure changes from perovskite orthorhombic (a=3.957898Ã?, b=5.641918Ã?, c=5.682394Ã?) to perovskite tetragonal (a=b=3.942611Ã?, c=4.011262Ã?). Electrical properties of these material were investigated using impedance analyzer. KNN exhibited two Curie temperature due to its phase …