Difference between local and average structures of LaGaSiO crystal

Yoneda, Yasuhiro   ; Takeda, Hiroaki*; Shiosaki, Tadashi*; Mizuki, Junichiro

The langasite (LaGaSiO, LGS) crystal grown by the Czochralski technique was investigated by X-ray diffraction measurements. The X-ray diffraction profiles of the LGS were consisted with sharp Bragg peaks and large amount of diffuse scatterings. The diffuse scattering inducated the existence of the local structure which is different from the average structure. The local structure was analyzed by the pair-distrivution function method. The local structure fluctuated by the chemical ordering of Ga and Si, and the local disordering feature of La.