X-Ray Diffraction

Introduction

X-ray diffraction (XRD) is a powerful technique used for the study of crystalline materials. By analyzing the way in which a beam of X-rays diffracts off a crystalline sample, one can determine the atomic and molecular structure of the material, including bond lengths and angles, atomic positions, and overall symmetry.

The Principle of XRD

The principle behind X-ray diffraction is Bragg’s Law, which describes the conditions under which constructive interference occurs. When X-rays are incident on a crystal lattice, the rays are scattered by the atomic planes within the crystal. The scattered rays undergo constructive interference when the path difference between them is an integer multiple of the wavelength.

Bragg’s Law is given as:

where:

• is the order of reflection, an integer,
• is the wavelength of the incident X-ray beam,
• is the interplanar spacing in the crystal lattice,
• is the incident angle.

XRD Analysis

In an XRD experiment, the sample is exposed to an incident beam of X-rays and the diffracted rays are detected and measured. The resulting pattern, known as a diffraction pattern, provides information about the crystal structure of the sample. Each peak in the diffraction pattern corresponds to a particular set of lattice planes within the crystal, and the position, intensity, and shape of the peak provides detailed information about the atomic structure.

Applications

X-ray diffraction has a wide range of applications in various fields such as materials science, geology, biology, and physics. It is used for phase identification in crystalline materials, determination of crystal structures, measurement of particle size in polycrystalline samples, and the study of thin films, among others.

Conclusion

X-ray diffraction is a key tool in the study of crystalline materials, providing invaluable information about their internal structure. The ability to probe the atomic-scale structure of materials has made XRD indispensable in a variety of scientific and industrial applications.

Do you prefer video lectures over reading a webpage? Follow us on YouTube to stay updated with the latest video content!

Want to study more? Visit our Index here!