Efficient fitting of single-crystal diffuse scattering in interaction space: a mean-field approach

Area of Science:

• Materials Science
• Crystallography
• Condensed Matter Physics

Background:

• Crystalline materials with correlated disorder exhibit structured diffuse scattering in diffraction patterns.
• Conventional analysis methods focus on atomistic interpretations or pairwise correlation parameters (e.g., Warren-Cowley).

Purpose of the Study:

• To demonstrate a mean-field methodology for directly fitting diffuse scattering data.
• To interpret diffuse scattering in terms of a microscopic interaction model.
• To reveal the physics governing correlated disorder.

Main Methods:

• Development and application of a mean-field methodology.
• Fitting diffuse scattering data directly using a microscopic interaction model.
• Utilizing a toy model based on diammine mercury(II) halides with correlated disorder.

Main Results:

• The mean-field approach enables efficient fitting of diffuse scattering.
• The methodology directly outputs the microscopic physics responsible for correlated disorder.
• The fitting process is robust to data incompleteness due to a minimal parameter set.

Conclusions:

• A mean-field method offers an efficient and robust way to analyze diffuse scattering.
• This approach provides direct insight into the physics of correlated disorder in crystalline materials.
• The technique is particularly advantageous for complex experimental conditions and limited data.