Chapter 5.3 Dynamical theory of neutron diffraction
Published Online: 1 JUN 2010
© International Union of Crystallography 2006
International Tables for Crystallography
How to Cite
Schlenker, M. and Guigay, J.-P. 2010. Dynamical theory of neutron diffraction. International Tables for Crystallography. B:654–664.
- Published Online: 1 JUN 2010
Dynamical scattering effects, such as Pendellösung oscillations, anomalous transmission, rocking-curve shapes or extinction, occur in neutron diffraction just as in the X-ray case. New features due to the neutrons magnetic moment appear in diffraction by magnetic crystals. The theory has to be formulated in terms of spinor wavefunctions. The dispersion surface, for the usual two-beam case, is of order 4, with wavefields polarized in various directions. If the mean value of the internal magnetic field and the Fourier component with wavevector equal to the scattering vector in the reflection under consideration of the microscopic magnetic field are parallel or antiparallel, this complicated situation is simplified: the propagation of the (±) spinor components are then independent of each other. Dynamical diffraction effects are involved in numerous neutron optics experiments and in the imaging of various types of magnetic domains by neutron topography.
Keywords: neutron scattering; dynamical theory; kinematical approximation; neutron interferometry; scattering lengths; refractive index; neutron absorption; Larmor precession; neutron spin; magnetic scattering; flipping ratio; extinction; Pendellösung; neutron topography