I am getting only the subtrate (electrode) peaks and not the electrodeposited samples peaks although i can see visually the smooth deposition of Ni and Ni(OH)2 onto it. I wonder what are the possibilities of not getting any PXRD peaks although EDAX and other elemental analysis prove its presence. The thickness of the deposition is about ~ 5-6 micrometers (from AFM and SEM cross sectional image).
Please suggest what might be the case.
Thank you
Hi!
Thickness is OK. What is the shape of your electrode? Is it a cylinder or rod? what is the exposed or activated area of your sample? whether the irradiated area is sufficient or not to diffract X-ray? Try to take a flat sample with smooth and plane surface and uniform coating thickness on it.
Again, what is the scanning speed try to choose a slow scan 0.5deg. /min, its is very important to get low conc. materials or elements.
Thank you sir.
My electrode exposed surface is flat and smooth. i will try with changing the measurement parameter like scan rate and longer time.
thank you very much
Have you registered the XRD pattern of the Ni(OH)2 you are using to check its crystallinity? The Ni(OH)2 used may have poor crystallinity that may not favor the charactristics peaks to be dissociated from the pattern baseline due to the relatively high XRD peaks of your substrate rate (Graphite).
Dear
May your deposition film is very thick or very thin and smooth which made inclined to the beam. So tray graduwally thin thickens film less than this until to find out the best result (peaks)
Good luck
The most simple reason could be that the deposited phase is amorphous. In your xrd pattern there is the presence of a broad peak at about 20°? Or is it possible to see bumps in the background?
If you don't have any technical problem (alignment of X-ray beam etc...) one reason would be the amorphous state of deposited film as Marcella and Jean-Aimé told. Other would be the poor signal coming from the film if the thickness is not enough. Another reason would be that the signal from the deposited film overlaps with the signal from the substrate (!).
One other thought - are you using grazing incidence? Set the tube angle at a suitable low value and scan only the detector to see the film.
Dear Jean Aimé Mbey,
I do agree with your suggestion that due to relatively high intensity of my substrate peaks and probably due to low crystallinity of my deposited sample, the peaks are not favorably dissociated in the diffraction pattern baseline. But how do i rectify it?
And can you please tell me more about the registering the Ni(OH)2 peaks that i am using to check the crystallinity? i have very little idea on the same.
Dear Marcella Bini,
Thank you very much for your answer. No there is no such broad peak at around 20 degrees (2 theta). Infact my blank substrate (graphite rod polished) is itself giving very sharp and intense peaks of its own and the same peaks are observed in case of the deposited films on this substrate. No there are no bumps in the background. How do i proceed to get better insight?
Dear Ian J Slipper ·,
Thank you very much for the suggestion. I think it might give some clue to me. I will try it and update for you further kind suggestions.
Dear Manjeet Chhetr, to check if your product cristallinity, you just have to registered the XRD pattern of the compound alone. To do so, you need an amorphous carrier for your sample. In case the sample is cristallized, then you will observed the product diffraction peaks. The peaks intensities and positions on the pattern may be useful to understand wether, when deposited on graphite, the peaks overlap graphite peaks or not.
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