X-ray diffraction was discovered by Max von Laue and works by detecting the scattering pattern of X-rays passing through a crystal. The document discusses how X-rays are scattered based on the arrangement of atoms in the crystal according to Bragg's law, which states that constructive interference occurs when the path difference of X-rays reflected from crystal planes is equal to an integer multiple of the wavelength. Common XRD methods include Laue diffraction, rotating crystal diffraction, and powder crystal diffraction. XRD is useful for determining crystal structures, identifying materials, and analyzing properties like purity and crystallinity.

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