X-ray Diffraction Homework: 2theta for (abc) and (def) Planes

[decerto]

Homework Statement

[/B]
A crystal composed of two fractions, one having the a cell parameters of x and the other of y are subjected to X-ray diffraction using both a Ni k-beta and a Zr b-beta radiation. Derive the angular position (2theta) for (abc) and (def) planes

Homework Equations

$n\lambda=d\sin\theta$
$d_{hkl}=\frac{x}{\sqrt{h^2+k^2+y2}}$

The Attempt at a Solution

First of all I am not sure what composed of two fractions means.

With the relevant equations it is pretty easy to solve this for a crystal composed of one "fraction" with one incident wavelength of xray. With two fractions and two incident wavelengths I am not sure if I should average over the the two spacings and the two wavelengths(The wording of the question implies there is one angular position for each plane) or if I do it for the 4 specific cases.

 

[Greg Bernhardt]

Thanks for the post! Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?