I wonder if output power of an X-Ray diffractometer can be adjusted. For Raman measurement it is possible. What about XRD? Does it change the penetration dept (if any) in a thin film?
The power of your x-ray generator will not change the energy of the x-rays, only the intensity, so it will have no effect on penetration depth. You will get better signal to noise ration which is useful for seeing the interference pattern at higher Q when doing reflectivity measurements of layered structures.
It depends on your equipment, samples and what you are trying to measure. You need to find the parameter space to optimize signal-to-noise, resolution, and scan time (for a given sample).
For example, using a Rigaku Smartlab we are able to get out-of-plane lattice constants of very few nms (~2) of epitaxial films using standard 2θ-ω scans.
If you have more details on the samples, and more importantly - what are you trying to measure, it would be easier to answer your question.
The power of your x-ray generator will not change the energy of the x-rays, only the intensity, so it will have no effect on penetration depth. You will get better signal to noise ration which is useful for seeing the interference pattern at higher Q when doing reflectivity measurements of layered structures.
Lawrence, if this addresses my comment - we are in agreement as I was referring to intensity and its effect on the SNR.
Lior,
No I was addressing the original question, which asked if it would effect the penetration depth, which of course it won't. Only using a higher energy source will do that. I agree with everything you said, I just didn't see anyone who had addressed the penetration depth issue.
Thanks a lot dear contributors.
Dr. Margulies, your answer was critical for me thank you.
Last question: what if I increase thickness to 1um range? Do not consider it as thin film.
I measure film (lets say film) on substrate, and back of it. Do you expect different patterns in ~1um thicknesses range?
Thanks in advance.
Substrate is Ni. I tried to coat LiV3O8 at 10-6 Torr vacuum. I approximately calculated its thickness as ~1um.
I think that if you're using a decent diffractometer then you shouldn't have any thin-film related difficulties. The only challenges I can see are overlap with substrate peaks, which, as you suggest, can be measured separately.
If you are using Cu K-alpha radiation then you should not see much if any scattering from the substrate with a 1 micron film thickness. Most definitely you will see a very different pattern measuring on either side.
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