Electron crystallography without limits? Crystal structure of Ti45Se16 redetermined by electron diffraction structure...

Area of Science:

• Materials Science
• Crystallography
• Solid-State Chemistry

Background:

• The crystal structure of metal-rich compounds presents unique challenges for determination.
• Electron diffraction is a powerful technique for analyzing crystalline materials at high resolution.

Purpose of the Study:

• To redetermine the crystal structure of the metal-rich compound Ti45Se16.
• To validate the application of direct methods using electron diffraction data for complex structures.
• To develop a method for estimating crystal thickness from refined structural parameters.

Main Methods:

• Selected-area electron diffraction (SAED) data collection.
• Quasi-automatic direct methods for structure solution.
• Least-squares refinement using the kinematical approximation.
• Analysis of quantified h0l electron diffraction intensities.

Main Results:

• The crystal structure of Ti45Se16 was refined in the monoclinic space group C2/m.
• Precise atomic coordinates with an average precision better than 0.05 Å were obtained.
• The refined structure showed good agreement (average difference of 0.18 Å) with previous high-resolution electron microscopy data.
• A novel method for estimating average crystal thickness was developed.

Conclusions:

• Direct methods are highly reliable for solving metal-rich structures using electron diffraction data, especially when elements have similar scattering power.
• The quasi-kinematical approximation is effective for refining structures from 2D SAED data.
• The developed method provides a reliable way to estimate crystal thickness, aiding in the interpretation of electron diffraction data.