Bragg’s Law (nλ = 2d sin θ) describes the conditions for constructive interference of X-rays scattered by a crystal lattice.
- n: Integer representing diffraction order.
- λ: Wavelength of incident X-rays.
- d: Interplanar spacing (distance between atomic planes).
- θ: Bragg angle (angle of incidence/reflection relative to the planes).
Constructive interference (and thus a detectable signal) occurs when the path difference between X-rays scattered from adjacent planes is an integer multiple of the wavelength. This path difference is represented by 2d sin θ.
Bragg’s Law relates the angle of incidence (θ), the wavelength of the X-rays (λ), and the spacing between the atomic planes (d) in a crystal. It allows the determination of crystal structures by analyzing the diffraction pattern produced when X-rays interact with the crystal.
The law assumes perfect crystallinity and ignores factors like thermal vibrations. It provides information about interplanar spacing, but not necessarily the arrangement of atoms within a plane.
