Question

If for a certain BCC crystal, the (110) plane has a separation of 1.181A and wavelength of 1.540A

Find the glance angle for the 1st line of the reflection.

B. Hence find the atomic radius

Answer 1

Bragg's Law 

$n\lambda= 2dSin\theta$

glance angle for the 1st line of the reflection.

$\theta = Sin^{-1}(\frac{1\times 1.540}{2\times 1.181}) =40.69^0$

atomic radius

$R = \frac{\sqrt3}{4}a= \frac{\sqrt3}{4}1.181 = 0.511$