Undergrad Is There an Analogous Law for X-ray Diffraction Minima?

[L_landau]

For x-day diffraction maxima we have braggs law
2d*sinθ = mλ (maxima)

Is there an analogous law for the minima like
2d*sinθ = (m+1/2)λ (minima?)

Thanks!

 

[jtbell]

Diffraction gratings don't have a simple alternating maximum/minimum pattern like the two-slit setup does.

http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/gratint.html

What you see are the primary maxima which are very narrow and bright. You don't normally see the secondary maxima and the minima in between them.

 

[M Quack]

For an ideal, infinite crystal, and using the kinematic theory of x-ray diffraction, there is intensity only at the Bragg positions, and nothing in between. Once you consider real (finite and imperfect) crystals and multiple scattering (dynamical theory of x-ray diffraction), things become a bit more complicated.

As an example, in surface diffraction, you get something called an "anti-Bragg" position.

https://en.wikipedia.org/wiki/X-ray_crystal_truncation_rod