Local Structure Analysis of KNbO₃ Nanocrystals with Cubic Shape

摘要： KNbO3 nanocrystals were grown by solvothermal technique assisted by a microwave treatment. The morphology of nanocrystals is a cubic shape and the crystal structure is also cubic system. This is an ideal case for the so-called Sherrer's equation. We performed high-energy X-ray scattering to extract various structural parameters. The particle size can be evaluated by the Sherrer's equation. The unit cell size of the KNbO3 nanocrystals was reduced as the particle size increased. The local structure of the nanocrystals was found to be a rhombohedral structure similar to that of the bulk KNbO3. Although the periodic structure of the perovskite system unchanged locally, the first-nearest neighbor and the second-nearest neighbor bond distances corresponding to Nb-O and K-O was changed as the particle size increased.