High resolution X-ray Diffraction

This module contains methods to create functors, which allow to simulate dynamical x-ray diffraction from strained crystals, multilayers, and superlattices.

The formalism is based on Stepanov et al publication [1]

The module allows to estimate the following profiles of structure parameters in multilayers:

• Normal lattice strains

• Crystal susceptibility \(\chi_0\), \(\chi_h\)

• Interface roughness

The Debay-Waller factors can be easily added to the model as dependent parameters.

The effects of lateral strains (relaxed multilayers, misfit dislocations, etc) are not simulated by this functor.

[1]

S.A.Stepanov, E.A.Kondrashkina, R.Koehler, D.V.Novikov, G.Materlik, and S.M.Durbin, “Dynamical x-ray diffraction of multilayers and superlattices: Recursion matrix extension to grazing angles”, Phys. Rev. B, 57, (1998) 4829-4841.

escape.scattering.spechrxrd.spechrxrd(name, variable_obj p0, multilayer_obj ml, h, k, l, beta=1.0, formalism='2x2')

Returns functor object for calculation of high resolution X-Ray diffraction.

Parameters:

p0: variable_obj

Variable, which represents z-component of wave-vector of incoming wave

ml: multilayer_obj

Sample description object

h: integer

Miller index of Bragg reflection

k: integer

Miller index of Bragg reflection

l: integer

Miller index of Bragg reflection

beta: double

Asymmetry factor \(\beta=g_0/g_h\)

‘formalism’: string

‘2x2’ matrix formalism works correctly far away from grazing incidence mode ‘4x4’ matrix formalism is valid for the whole range

Returns:

functor_obj instance