Calculation of total scattering from a crystalline structural model based on experimental optics parameters

Area of Science:

• Materials Science
• Crystallography
• Condensed Matter Physics

Background:

• Total scattering measurements reveal structural disorder in crystalline materials via Fourier transformation of the total structure factor, S(Q).
• Accurate calculation of total scattering intensity requires a Q-broadening function accounting for instrumental and intrinsic parameters.

Purpose of the Study:

• To propose a direct calculation method for total scattering from crystalline structural models.
• To validate the method using X-ray total scattering data of CeO2 powder under various optical conditions.

Main Methods:

• Developed a direct calculation approach for total scattering intensity.
• Incorporated a Q-broadening function to account for instrumental parameters like X-ray energy resolution and divergence.
• Performed X-ray total scattering measurements on CeO2 powder at the SPring-8 synchrotron facility.

Main Results:

• The evaluated Q-broadening function closely matched the experimental Bragg peak widths.
• The proposed calculation method accurately incorporated Q-dependent parameters, including atomic form factors and resolution functions.
• Successfully estimated the total scattering factor and determined the reduced pair distribution function.

Conclusions:

• The direct calculation method provides a reliable way to analyze total scattering data.
• This method facilitates the determination of structural disorder and pair distribution functions for both crystalline and amorphous materials.
• The approach is valuable for understanding materials at an atomic level.