Difference between Local and Average Structures of La3Ga5SiO14 Crystal

Abstract

The langasite (La3Ga5SiO14, LGS) crystal grown by the Czochralski technique was investigated by X-ray diffraction measurements. The X-ray diffraction profiles of the LGS consisted of sharp Bragg peaks and large amounts of diffuse scatterings. The diffuse scatterings indicated the existence of a local structure, which is different from the average structure of LGS. The local structure was analyzed by the pair-distribution function method. The local structure fluctuated owing to the local disordering of La atoms.