Chapter 47: Problem 38

Question: Assume that the incident x-ray beam in Fig27, Chapter 47, is not monochromatic but contains wavelengths $\lambda$in a band from 95 to $139~{\rm pm}$. Will diffracted beams, associated with the planes shown, occur? If so. what wavelengths are diffracted? Assume $d~=~275~{\rm pm}$.

Solution:

$$d\sin\theta~=~275\sin (90-42.2)~=~203.72~{\rm pm}$$

which can be satisfied at m = 2 by $\lambda~=~101.86$.