Local structure and phase transitions of KNbO₃

Bond length distributions of nearest- and higher-neighbor distances in KNbO3, which is the parent compound of lead-free piezoelectric materials, have been obtained by X-ray pair-distribution function (PDF) analysis. The Rietveld analysis of high-energy powder X-ray diffraction data as a function of temperature from 15 to 1073 K over four phases shows the variation in structure from rhombohedral to cubic structures. The refinements on the local...