Question

what are two experimental considerations when running PXRD (powder X-ray diffraction) using a flat disk sample holder? And why is the scan time and 2theta range important parameters in the experiment?

Answer 1

Power X-Ray diffraction is a analytical technique which is rapid and being used for identification of phase for the crystalline material and would help in providing information on dimension of unit cells. Some considerations need to be taken when the experiment is being performed using flat disk sample holder. It is a bulk technique. The first consideration is that the experiment cannot be performed on single particle or material with small range, it is a bulk technique and will be experimented if particles are in bulk quantity. The other one is that it act as three dimensional diffraction gratings for X-Ray wavelength similar to the spacing planes present in the crystal lattice.

A diffraction spectrum consists of relationship between the reflection intensities and 2theta. That relationship depends on the goniometer configuration. The theta values has a role in peak dependence of the wavelength and reflection intensity will depend on the scan time and by these two parameters some changes are being observed in the diffraction spectrum and this experiment of power X-Ray diffraction is totally dependent on diffraction as well as the wavelength of the bulk particles.