Bragg’s Equation

Crystal structures are studied by x-ray diffraction method.

It is due to the interatomic differences and interplanar distances in a crystal are in the range of wavelength of x-rays.

Only in the case of x-rays diffraction is possible.

Path difference = BC + CD

                          = AC sinθ + AC sinθ

                          = d sinθ + d sinθ

                          = 2d sinθ

According to the Bragg’s

Path Difference α λ

2d sinθ α λ

(or)

2d sinθ = nλ

d = distance between atomic layers