# Bragg Diffraction vs. Laue Diffraction: What's the Difference?

Edited by Aimie Carlson || By Janet White || Published on February 4, 2024
Bragg Diffraction refers to the scattering of waves, like X-rays, off crystalline materials at specific angles. Laue Diffraction involves the diffraction of X-rays through a crystal, creating a pattern of spots.

## Key Differences

Bragg diffraction occurs when waves are scattered from a crystalline structure and interference occurs at specific angles, following Bragg's Law. Laue diffraction, on the other hand, involves passing X-rays through a stationary crystal, forming a distinct spot pattern.
In Bragg diffraction, the incident angle and wavelength are variable while the crystal's orientation is fixed. Laue diffraction contrasts this by keeping the wavelength and angle fixed, but varying the crystal orientation.
Bragg diffraction is typically used for examining crystal structures using a monochromatic X-ray source. Laue diffraction is more suited for identifying the orientation of crystals, especially using polychromatic X-ray sources.
The Bragg method is ideal for measuring distances between atomic planes in crystals. Laue diffraction provides a more comprehensive view of the symmetry of the crystal structure.
Bragg's approach is often used in powder diffraction studies. Laue method is more commonly employed in single-crystal diffraction studies.

## Comparison Chart

Variable
Fixed

### Wavelength

Monochromatic (single wavelength)
Polychromatic (multiple wavelengths)

Fixed
Variable

### Primary Use

Crystal structure analysis
Crystal orientation identification

### Type of Crystal Used

Powdered or single crystal
Primarily single crystal

## Bragg Diffraction and Laue Diffraction Definitions

#### Bragg Diffraction

Involves a fixed angle of X-ray incidence.
In Laue diffraction, the incident angle of the X-rays remained constant.

#### Laue Diffraction

Uses polychromatic X-rays for diffraction.
Laue diffraction was performed with a polychromatic X-ray source.

#### Bragg Diffraction

Useful in examining crystal symmetries.
Symmetry elements of the crystal were identified through Laue diffraction.

#### Laue Diffraction

Primarily used for analyzing single crystals.
The single crystal's orientation was determined using Laue diffraction.

#### Bragg Diffraction

Forms a distinct pattern of spots on a photographic plate.
The Laue diffraction resulted in a clear spot pattern.

#### Laue Diffraction

Forms a distinct pattern of spots on a photographic plate.
The Laue diffraction resulted in a clear spot pattern.

#### Bragg Diffraction

Primarily used for analyzing single crystals.
The single crystal's orientation was determined using Laue diffraction.

#### Laue Diffraction

Involves a fixed angle of X-ray incidence.
In Laue diffraction, the incident angle of the X-rays remained constant.

#### Bragg Diffraction

Uses polychromatic X-rays for diffraction.
Laue diffraction was performed with a polychromatic X-ray source.

#### Laue Diffraction

Useful in examining crystal symmetries.
Symmetry elements of the crystal were identified through Laue diffraction.

## FAQs

#### Can Bragg diffraction use polychromatic X-rays?

It typically uses monochromatic X-rays.

Bragg's Law.

#### In Laue diffraction, is the crystal orientation fixed?

No, it's variable.

#### How does Laue diffraction differ in X-ray usage?

It uses polychromatic X-rays.

#### Is Laue diffraction suitable for single crystals?

Yes, especially for single crystals.

#### Is Laue diffraction used for determining atomic distances?

It's more focused on crystal orientation.

#### What is a common application of Bragg diffraction?

Powder diffraction studies.

#### Can Laue diffraction analyze crystal symmetry?

Yes, it's effective for this purpose.

#### What is Bragg diffraction primarily used for?

Analyzing crystal structures.

#### What type of pattern does Laue diffraction create?

A distinct spot pattern.

#### Is the incident angle fixed in Bragg diffraction?

No, it's variable.

#### How is Laue diffraction typically conducted?

By passing X-rays through a crystal and observing the pattern.

#### What type of X-rays does Bragg diffraction typically use?

Monochromatic X-rays.

#### Is Laue diffraction suitable for powder samples?

It's best suited for single crystals.

#### Does Bragg diffraction use a fixed crystal orientation?

Yes, the crystal orientation is fixed.

#### What's the advantage of Laue diffraction for crystal studies?

It provides a comprehensive view of crystal symmetry.

#### Can Bragg diffraction be used for single-crystal studies?

Yes, but it's also used for powdered samples.

#### Does Laue diffraction require a fixed incident angle?

Yes, the incident angle is fixed.

#### How does Bragg diffraction analyze crystals?

Through X-ray scattering and interference patterns.

#### What's a key feature of Bragg diffraction in crystallography?

Its ability to measure interplanar spacings.