If I prepare CuFe2O4 Sample. And I apply Cu target on the sample in the XRD. So, will there be any effect on our sample?
Dear Sanjeet Kumar Paswan ,
your sample material will not be affected by the x-ray radiation.
But your XRD pattern will be affected by a background due to the Fe K-fluorescence, which is excited by the Cu K-apha radiation of the Cu x-ray tube.
There are two ways to overcome this shortcoming:
a) use a monochromator in front of detector or energy dispersive detection to detect only the Cu K-alpha; or
b) use a Co or Cr target; Co and Cr K-alphas are not able to excite the Fe K fluorescence.
Good luck and
best regards
G.M.
One may add that even in the case of use of a Cu tube and of a diffracted-beam monochromator the white raditiation from the tube will generate Cu fluorescence in you sample, which will contribute to you background as it goes "through" the monochromator. So Fe fluroscence may not be the only problem.
Thanks, Andreas Leineweber ,
for the hint on the Cu fluorescence, which will be excited via the high energy part of the tube's bremsspectrum above Cu K-edge energy.
But I think, the Cu fluorescence background might be small because the x-ray K-shell attenuation cross-section rapidly goes down above the Cu K-edge energy (~8,9keV) for increasing photon energy (see the attached diagram). So only a small section of the bremsspectrum will significantly cause Cu fluoresecence background contribution.
Sanjeet Kumar Paswan , you should make a test scan with Cu tube. If the background is too large and you cannot handle this issue, then you have the alternative of option (b), using Co or Cr target, including option (a) monochromator/energy dispersive detection of Co or Cr K-alpha.
Good luck and
best regards
G.M.
Dear Gerhard Martens,
this effect was at least sufficiently strong to surprise me with the high background level when I measured Co powder with CoKalpha radiation on a machine with diffracted beam monochromator many years ago. Prior to this, I was not even aware of this effect. Of course, this effect does not occur upon use of a primary beam monochromator.
https://www.researchgate.net/publication/323214279_X-Ray_Diffraction_of_Iron_Containing_Samples_The_Importance_of_a_Suitable_Configuration
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