This presentation covers the basics of XRD and XRD methods. For more information, please refer the book which is mentioned in the references slide

1. Seminar On
X – Ray Diffraction Technique
and
Diffraction Methods
Melwin D’mello
M.E (Welding Engineering)
Centre for Materials Joining & Research (CEMAJOR),
Department of Manufacturing Engineering,
ANNAMALAI UNIVERSITY
Presented by

2. CONTENTS
• Introduction
• Generation of X-ray
• X- ray region
• X- ray diffraction
• XRD Principle
• XRD Equipment
• Diffraction Methods
• Applications of XRD Methods
• References

3. INTRODUCTION
• X- rays were discovered by Wilhelm Roentgen who called
them “X-rays” and it is also called as “Roentgen Rays”.
• X- ray diffraction was discovered by Max Von Laue in 1912.
• X- rays are electro magnetic radiation with wavelengths in
the range 0.1 to 100 A o .
• X- rays used in diffraction experiments have typical
wavelengths of 0.5 to 1.8 A o.

4. GENERATION OF X-RAYS

5. X - RAY REGION

6. X-RAY DIFFRACTION ( XRD )
• These methods are based on the scattering of X-ray
crystals.
• When x-rays interact with a solid material, the scattered
beams causes diffraction.

7. XRD PRINCIPLE
• Different Planes in a crystal give different signals
equal to positive interface of waves.

8. XRD EQIPMENT

9. X-Ray
Diffraction
Method
1. Laue’s
Method
2. Rotating
Crystal
Method
3. Powder
Method
EXPERIMENTAL
DIFFRACTION METHODS

10. • In this method a single crystal is held stationary in the path
of radiation of continuous wavelength. While  is kept
constant, the wavelength ,  is varied.
• A plane film receives the diffracted beams. A developed
film after its exposure shows a diffraction pattern that
consists of series of spots.
1. LAUE’S METHOD

11. Laue’s method is divided
Into two types
a) Transmission Method
b) Back Reflection Method

12. a) Transmission Method
A beam of x-ray is passed through the crystal,
after passing through the crystal, x-rays are diffracted
and recorded on a photographic plate.

13. a) Transmission Method

14. b) Back Reflection Method
This method provides similar information as the
transmission method.

15. 2. ROTATING CRYSTAL
METHOD

16. Rotating Crystal Method cont…
• In this method , a single crystal is rotated about the fixed
axis in a beam of monochromatic. The angle  is variable
while the wavelength is kept constant.
• The variation of angle  due to rotation of the crystal brings
different atomic planes in the crystal into position.
• To record such reflections a film is mounted on a cylindrical
holder that is concentric with a rotating spindle.

17. • This method is useful for samples that are difficult to
obtain in single crystal form.
• The powder method is used to determine the value of the
lattice parameters accurately.
3. POWDER METHOD

18. • A sample of hundreds of powdered crystals show that the
diffracted beams form continuous cones.
• A circle of film is used to record the diffraction pattern.
• Each cone intersects the film giving diffraction lines.
• The lines are seen as arcs on the film.
The powder method cont…

19. APPLICATIONS OF XRD
METHODS
• Determination of crystal size and shape.
• Particle size determination by spot counting methods.
• Crystallographic structural analysis.
• Unit cell calculations for crystalline materials.
• Identification of single and multi phase materials

20. REFERENCES
1. “Instrumental Methods Of Chemical Analysis” by
Gurudeep R Chatwal.
2. https://en.wikipedia.org/wiki/X-ray_crystallography