Local structure and phase transitions of KNbO

Yoneda, Yasuhiro   ; Ohara, Koji*; Nagata, Hajime*

Local structure analysis of KNbO, which is the parent compound for lead-free piezoelectric materials, have been performed by X-ray pair-distribution functions (PDF). The refinements of local structure in wide temperature ranges indicates that only the rhombohedral structure can describe the observed bond distributions within the unit cell. The rhombohedral distortion maintained locally in all four phases.