BRAGG`S LAW,X-RAY DIFFRACTION AND METHODS,APPLICATIONS OF X-RAY DIFFRACTION.

1. Submitted by;
Naveen Raj. P
Pasupathi. C
VINAYAGA MISSIONS COLLEGE
OF PHARMACY SALEM

2. INTRODUCTION:
 X-rays discovered by Wilhelm Roentgen;
 Known as x-rays because nature at first was unknown so, x-
rays are also called Roentgen rays;
 X-ray diffraction in crystals was discovered by Max von
Laue;
 The wavelength range is 0.01 to 10 nm (Frequency range of
30 petahertz to 30 exahertz)
 There are two types of x-rays:
- Hard x-rays: which have high frequency and have
more energy.
- Soft x-rays: which have less frequency and have low
energy

3. X-Ray Diffraction (XRD)
Diffraction : X-rays are scattered from the atoms in the
sample. The rays scattered from the different atoms interfere
with one another either constructively or destructively.

4. Working Principle:
X-rays when passed through a crystal sample, X-rays are
scattered based on the arrangement of the atoms in the crystal.
Within a crystal, atoms are arranged in plane with a particular
distance in each axis viz., x, y and z.
When X-rays of a wavelength similar to the inter-planar distance
between the atoms, the rays diffract.
Braggs Eqn.: n = 2d Sin 
n = integer
 = wavelength of X-ray
d = atomic layer distance
 = angle of incidence

5. BRAGG’S LAW: Constructive interference of the reflected
beams emerging from two different planes will take place if the
path lengths of two rays is equal to whole number of
wavelengths

6. X-Ray Diffraction Methods: Generally used methods for the
internal structural investigations

7. Laue Diffraction Method

8. Rotating Crystal Diffraction Method

9. Powder Crystal Diffraction Method

10. Applications
 Useful for determining the complex structures of metals and
alloys
 Characterization of crystalline materials
 Identification of fine-grained minerals such as clays and mixed
layer clays that are difficult to determine optically
 Determination of unit cell dimensions
 Measurement of sample purity

11. Structure of Crystals
Polymer Characterization
Identification Of Impurity
Particle size analysis
Degree of crystallinity
Applications of diffraction methods to complexes
a) Determination of cis-trans isomerism
b) Determination of linkage isomerism

12. Thank you