X射线衍射（XRD）

X-ray Diffraction (XRD) Analysis

X-ray Diffraction (XRD) is a powerful, non-destructive technique used to characterize crystalline materials. It provides information about crystal structure, phase composition, preferred crystal orientation (texture), and other structural parameters such as average grain size, crystallinity, strain, and crystal defects.

The XRD technique works by generating X-ray diffraction peaks through constructive interference of a monochromatic X-ray beam diffracted at specific angles from each set of lattice planes in the sample. The peak intensities are determined by the atomic arrangement within the crystal lattice. Therefore, the XRD pattern serves as a unique fingerprint of the periodic atomic arrangement in a given material. By searching the ICDD (International Centre for Diffraction Data) database, phase identification can be performed for various crystalline samples.

XRD is featured in our Smart Chart series.

EAG's multiple XRD systems are equipped with interchangeable optical modules that can be changed without affecting positioning accuracy. The systems can easily switch between line-focus and point-focus X-ray sources, allowing simple transition from conventional XRD to high-resolution XRD configurations as needed. Different optical module combinations enable analysis of powders, coatings, thin films, slurries, manufactured components, or epitaxial films. EAG also possesses a micro-diffractometer with a 50D area detector for small-spot (<2 µm) XRD analysis, delivering excellent signal-to-noise ratio even with small X-ray beam sizes.

Primary Applications of XRD Analysis:

1. Identification/quantification of crystalline phases

2. Measurement of average crystallite size, strain, or microstrain effects in bulk materials and thin films

3. Quantification of preferred orientation (texture) in thin films, multilayer stacks, and manufactured components

4. Determination of crystalline-to-amorphous ratio in bulk materials and thin films

5. Phase identification for various bulk and thin film samples

6. Detection of minor crystalline phases (concentration >~1%)

7. Determination of crystallite size in polycrystalline films and materials

8. Quantification of crystalline vs. amorphous content

9. Phase identification from sub-milligram loose powder or dried solution samples

10. Analysis of texture and phase behavior in thin films (as thin as 50Å)

11. Determination of strain and composition in epitaxial films

12. Identification of surface cuts in single crystal materials

13. Measurement of residual stress in bulk metals and ceramics

Advantages of XRD:

1. Non-destructive nature

2. Quantitative measurement of phases and texture orientation

3. Minimal or no sample preparation requirements

4. All analyses performed under ambient conditions

Limitations of XRD:

1. Cannot identify amorphous materials

2. No depth profiling capability

3. Minimum spot size approximately 25 µm

Technical Specifications:

• Detected signal: Diffracted X-rays

• Detectable elements: All elements (assuming they are present in crystalline form)

• Detection limit: ~1% for multiphase quantitative analysis

• Minimum film thickness for phase identification: ~20Å

• Depth resolution: Sampling depth ranges from ~20Å to ~30µm, depending on material properties and X-ray incidence angle

• Imaging/mapping: Not available

• Lateral resolution/probe size:

  • Point focus: 0.1mm to 0.5mm

  • Line focus: 2mm to 12mm

  • Micro-diffraction: ~20µm

Additionally, please read our application note on High-Resolution X-ray Diffraction (HR-XRD) Measurements of Compound Semiconductors, which discusses how this method can determine the composition and thickness of semiconductors such as SiGe, AlGaAs, InGaAs, and other materials.

In summary, EAG provides XRD services to analyze a wide range of materials for our clients. You can rely on fast turnaround times, accurate data, and personalized service to ensure you fully understand the information you receive.

Finally, contact EAG Laboratories today at 877-709-9526 or complete our online form to have an expert contact you about how we can use this XRD testing service to analyze your materials.