X-ray diffraction, basic principle, instruments, Bragg's law, diffraction and applications.pptx

X-RAY Diffraction
1.Introduction
2.What is X-Ray?
3.Basic principle
4.Instrumentation
5.Bragg’s Law and X-Ray
6.Diffraction
7.Applications

INTRODUCTION:
X-rays are electromagnetic waves having wavelength in range of 0.1-100Å.
X-rays used in diffraction techniques have typical wavelength of 0.5-1.8Å.
X-rays were discovered by Wilhelm Roentgen who called them X-rays and it is also called as Roentgen rays.
BASIC PRINCIPLES:
In an atom, the electrons are arranged in layers or shells, like
K-shell
L-shell
M-shell
N-shell.
When the atom is bombarded with an electron, eject one of the electron from the inner shell.
The electrons migrate from the outer shell to the inner shell to fill the gap with higher energy.
A quantum of radiation (X-rays) is emitted corresponding to this transition, time scale is approximately 10-12-10-14 sec.
Emitted radiation is called X-rays.

X-RAY DIFFRACTION PRINCIPLE:
X-ray diffraction is based on constructive interference of monochromatic X-ray and a crystalline sample.
These rays are generated by a cathode ray tube, filtered to produce monochromatic radiation, collimated to concentrate and directed towards the sample.
The interaction of incident rays with the sample produces constructive interference when conditions satisfy Bragg’s law.

INSTRUMENTATION:
1.X-ray tube
2.Collimator
3.Monochromator
4.Filter
5.Crystalmonochromator
6.Detectors

APPLICATION OF X-RAY DIFFRACTION:
Identification of single-phase materials, minerals, chemical compounds and ceramics.
Identification of multiple phase in microcrystalline mixture(rocks).
Determination of crystalline size and shape.
Crystallographic structural analysis and unit cell calculation from crystalline materials.
Particle size determination-Spot counting methods.

1. X-RAY Diffraction

2. OUTINE OF X-RAY DIFFRACTION Introduction What is X-Ray? Basic principle Instrumentation Bragg’s Law and X-Ray diffraction Applications

3. INTRODUCTION X-rays are electromagnetic waves having wavelength in range of 0.1-100Å . X-rays used in diffraction techniques have typical wavelength of 0.5-1.8Å . X-rays were discovered by Wilhelm Roentgen who called them X-rays and it is also called as Roentgen rays.

4. REGION OF X-RAYS

5. BASIC PRINCIPLE In an atom, the electrons are arranged in layers or shells, like K-shell L-shell M-shell N-shell

6. Contd … When the atom is bombarded with an electron, eject one of the electron from the inner shell. The electrons migrate from the outer shell to the inner shell to fill the gap with higher energy. A quantum of radiation (X-rays) is emitted corresponding to this transition, time scale is approximately 10 -12 -10 -14 sec. Emitted radiation is called X-rays.

7. X-RAY DIFFRACTION PRINCIPLE X-ray diffraction is based on constructive interference of monochromatic X-ray and a crystalline sample. These rays are generated by a cathode ray tube, filtered to produce monochromatic radiation, collimated to concentrate and directed towards the sample. The interaction of incident rays with the sample produces constructive interference when conditions satisfy Bragg’s law .

8. INSTRUMENTATION X-ray tube Collimator Monochromator Filter Crystal monochromator Detectors

9. X-ray tube: High velocity of electrons bombarded on target metal, X-rays are produced. Collimator: Closed metal plates separated by small gap. Use is to produce narrow beam. Monochromator: Absorb the undesirable radiations and allows required wavelength to pass. INSTRUMENTATION

10. Detectors: Photographic methods Counter methods Types: Geiger-Muller counter Proportional counter Scintillation counter Solids state semiconductor counter INSTRUMENTATION

11. INSTRUMENTATION

12. The relationship describing the angle at which a beam of X-rays of a particular wavelength diffracts from a crystalline surface was discovered by William Bragg and Lawrence Bragg and is known as Bragg’s Law . BRAGG’S LAW AND DIFFRACTION

13. APPLICATION OF X-RAY DIFFRACTION Identification of single-phase materials, minerals, chemical compounds and ceramics. Identification of multiple phase in microcrystalline mixture(rocks). Determination of crystalline size and shape. Crystallographic structural analysis and unit cell calculation from crystalline materials. Particle size determination-Spot counting methods.

14. XRD pattern of CuO NPs

15. Recommended book Biochemistry Laboratory: Modern Theory and Techniques Rodney Boyer ( Hope College) Second Edition Chapter 7: Spectroscopic Analysis of Biomolecules E. (X-ray crystallography)

16. THANK YOU