Structure Analysis by Wide-Angle Neutron Diffraction Method

Abstract

The crystal structure analyzed by X-ray diffraction method must be checked from the different point of view. The wide-angle neutron diffraction is one of the most powerful methods for this purpose. The principle of wide-angle neutron diffraction phenomenon is leaned at first in comparison with the X-ray diffraction. The experiment of neutron diffraction is made using a neutron beam from the atomic reactor with a nuclear fission of Uranium or using neutron pulses generated by spallation. The principles of these different experimental methods are learned. At the next stage, the process to determine the crystal structure using the neutron diffraction data is learned by focusing the difference from the X-ray diffraction analysis. The Fourier transformation of the X-ray and neutron diffraction data gives the electron density distribution and the nuclear atomic positions, respectively. The combination of these two different information (X-N method) allows us to know the distribution of electrons contributing to the covalent bonds along the polymer chains.KeywordsNeutron diffractionScattering cross-sectional areaCrystal structure analysisTime-of-flight methodX-N method