3D Recipricol Space Mapping of Nanowires by using x-rays

poul

Hey

I have a x-ray setup as in the figure, where alpha is the angles between the incoming x-ray beam and the sample. The x-ray are scattered, and measured by a 2D detector in the two outgoing angles. From this i will get a "slice" of the 3D recipricol map. If a want a 3D map, i think i will get nothing by rotating the sample i omega, since the nanowire planes have random orientation in omega. Instead i should change alpha. I this the right procedure?



http://imageshack.us/photo/my-images/32/setupso.jpg/

M Quack

If you have a powder sample (or randomly oriented nanowires), then all diffraction data you get will only depend on the scattering angle, i.e. the angle between the inciden beam and the exit beam (which you can calculate from the position on the 2D detector).

If you have a monolayer of nanotubes then you signal will also depend on the angle between the incident beam and the substrate.

In both cases, rotating the sample about the substrate surface normal will not give any new information, except if the nanotubes are aligned with some substrate direction (steps, ...).