Chapter 11, Problem 11.84QE

Interpretation Introduction

Interpretation:

The wavelength of x-ray diffraction has to be given.

Concept introduction:

Bragg equation:

Bragg diffraction occurs when radiation, with a wavelength comparable to atomic spacing is scattered in a regular fashion by the atoms of a crystalline system and undergoes constructive interference.  For a crystalline solid the waves are scattered from lattice planes separated by the interplanar distance $\left(\text{d}\right)$ When the scattered waves interfere constructively they remain in phase since the difference between the path lengths of the two waves is equal to an integer multiple of the wavelength.  The path difference between two waves undergoing interference is given by $\text{2dsinθ}$.

Figure 1

The Bragg equation is,

  $\text{nλ=2dsinθ}$

Where,

$\text{λ=}$ wavelength of the x-ray

$\text{d}$=interplanar distance

$\text{θ}$=incident angle

$\text{n}$=integer