2018 : Local distortion determination of the (1 − x) (K0.5Na0.5)NbO3 − x (Ba0.8Sr0.2)TiO3 system and their influence on the electrical properties

Prof. Dr. Suasmoro


Abstract

The composition of (1 − x) (K0.5Na0.5)NbO3 − x (Ba0.8Sr0.2)TiO3 and termed as (1 − x) KNN – x BST for x = 0, 0.1 and x = 0.2 were successfully synthesized using a combination of solid-state reaction and co-precipitation oxalate methods. Structure and local distortion determination were carried out using X-Ray diffraction (XRD), and X-ray absorption spectroscopy (XAS) Ti K-edge data. The XRD was utilized to investigate the phase present in the sample and crystal structure determination through Rietveld refinements, while local distortion due to the defects were studied by XANES and EXAFS at the Ti K-edge. XRD analysis at room temperature concluded that both KNN–BST samples exhibit tetragonal structure compared to orthorhombic for KNN, while EXAFS analysis using Artemis software revealed the oxygen octahedral distortion and distance of Ti Nb …