Bragg's law

 

Bragg's law is a special case of Laue diffraction, which determines the angles of coherent and incoherent scattering from a crystal lattice. When X-rays are incident on a particular atom, they make an electronic cloud move like an electromagnetic wave. The movement of these charges radiates waves again with similar frequency, slightly blurred due to different effects, and this phenomenon is known as Rayleigh scattering. Basically, this law explains the relationship between an x-ray light shooting and its reflection from a crystal surface.   

2dsinθ =n λ The crystal can diffraction x-ray because the interplanar  spacing in the crystal lattice is of the same order as that of wavelength of x-ray  Application of Bragg's law

In the case of XRF (X-ray fluorescence spectroscopy) or WDS (Wavelength Dispersive Spectrometry), crystals of known d-spacings are used for analyzing crystals in the spectrometer

Bragg's Diffraction

Bragg's diffraction was first proposed by William Henry Bragg and William Lawrence Bragg, in 1913. Bragg's diffraction occurs when a subatomic particle or electromagnetic radiation waves have wavelengths that are comparable to atomic spacing in a crystal lattice.

• In XRD (X-ray diffraction) the inter-planar spacing or d-spacing of a crystal is used for characterization and identification purposes.