When X-rays with λ = 0.7873 Å are used, the second-order Bragg reflection from a set of parallel planes in a niobium crystal occurs at an angle θ = 24.41°.

Question

When X-rays with λ = 0.7873 Å are used, the second-order Bragg reflection from a set of parallel planes in a niobium crystal occurs at an angle θ = 24.41°. Calculate the distance between the planes in the crystal.

Answer 1

Bragg equation is 2dsin(θ_n) = nλ where θ is the angle to the layer,surface, not to the normal as for any other refraction problem.

In your case , you want n = 2 or d = λ/sin(θ)

The units are still in angstroms.