The Development of Three-Dimensional Differential Pair Distribution Function Method for Shanghai Synchrotron Radiation Facility

Benefited from the high brightness and intensity of next-generation synchrotron radiation sources, 3D-ΔPDF can provide unprecented insight into the local structure of materials at the atomic level. [Purpose] This study aims to promote the implementation of the three-dimensional differential atomic pair distribution function method at different energy beamlines of the Shanghai Synchrotron Radiation Facility (SSRF) and to verify its effectiveness and reproducibility in the local structure analysis of single-crystal materials. [Methods] Single crystal experiments were conducted on PbTe and Zr0.91Y0.09O29 (YSZ) samples at the BL12SW beamline of SSRF, resulting in three-dimensional total scattering datasets.

The 3D-ΔPDF method was employed to remove the Bragg diffraction signals and directly analyze the correlation functions in three-dimensional space. [Results] The results demonstrate that under low-temperature conditions, the reduction of thermal vibration-induced diffuse scattering significantly enhances the resolution of 3D-ΔPDF experiments. This approach reveals the presence of local symmetry breaking in the PbTe system, providing critical insights into the structural origins of its exceptional thermoelectric properties.