Structural Defect Characterization

Our Defect Characterization Platform

Defect states in colloidal crystals can affect the energy transfer between the crystal and the environment, further affecting their applications. Alfa Chemistry can use analytical techniques to obtain information about these defects. Our methods include but are not limited to:

• Electron Backscatter Diffraction(EBSD)

EBSD is a technique derived from Scanning Electron Microscopy (SEM). By placing a fixed electron beam at a selected sampling point on the surface of the sample, crystallographic information such as grain orientation, grain orientation distribution (micro-texture), and orientation relationship of the sample can be obtained. As a surface analysis method, EBSD can quantitatively describe the regional microstructure in terms of directional components.

Fig.1 Typical view of EBSD hardware inside microscope chamber.^[2]

• High-Resolution Transmission Electron Microscopy(HRTEM)

HRTEM can use light and dark fringes to represent the interplanar spacing and can be used to analyze crystal structure and lattice defects in various advanced materials at atomic resolution. It can be used to characterize structures such as point defects, stacking faults, dislocations, and precipitate grain boundaries.

• Thermally stimulated luminescence(TSL)

Using the TSL technique in parallel with other measurements can provide information on the electronic level of material defects.

Fig.2 Schematic representation of a typical TSL measuring system.^[3]

Application Scope of Our Services

• Research and development: for basic research on photonic crystals and testing of new materials
• Production: Quantitative Analysis of Defects; Topography Characterization; Quality Control
• Technological Improvement: Analyze the relationship between defects and colloid properties, optimize preparation technology
• Error analysis: compare the gap between theoretical defects and actual defects, analyze the reasons

References

1. Wan Yong, et al. Effects of Planar Defects on Optical Properties in Three-Dimensional Colloidal Crystals. Acta Optica Sinica. 2009.
2. Randle, Valerie. Application of Electron Backscatter Diffraction to Grain Boundaries. Solid State Phenomena. 2010, 160:39-46.
3. Martini M,  Meinardi F. Thermally stimulated luminescence: New perspectives in the study of defects in solids. La Rivista del Nuovo Cimento. 1997, 20(8):1-71.

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