Diffuse Neutron Scattering from Cubic Lithium Sulphate at 908 K

抄録

The diffuse neutron scattering intensity for Li₂SO₄ at 908 K has been calculated using a treatment which includes correlation between thermal displacements of the atoms and reorientation of the SO₄²⁻ ions. The calculation of the diffuse neutron diffraction scattering for Li₂SO₄ powder is based on a structural model obtained from a recent analysis of single crystal neutron Bragg reflections for the high temperature cubic phase of Li₂SO₄. Relatively large correlations are required between the displacements of the atoms (λ_s(S)s(O) and λ_{sn(O)sn′(O)} for n≠n′) to obtain good agreement between calculated and observed diffuse intensities. It is shown that evidence for a “paddle-wheel mechanism” is difficult to obtain from an analysis of the diffuse neutron scattering intensities.