I obtained a XRD diffractogram with significant broad band at low 2theta levels, also around 30 2theta another smaller broad band appears. It all points out to the existence of an amorphous phase. The SEM-EDX points out Mg, P and O in the sample. The structure it formed is a common one for a specific magnesium phosphate, and some of its peaks are faintly visible if we ignore the broad bands. My question is can the amorphous phases present or even the presence of carbon materials mask the presence of a crystaline phase?
Or maybe, as I didn't have as much material for the analysis and a microsampling was used, can it have caught mainly the amorphous phase only and not the crystal phase under it?
Dear Denis Rodrigues ,
carbon has a quite low atomic number and thus has low x-ray attenuation. So I think carbon will not 'mask' crystalline material. This also holds for O, P and Mg.
As you already mentioned by yourself, I think you will accidently have picked up too less amount of the crystalline phase(s), if present at all in your sample.
'faintly' visible peaks? I do not see any one, even when I zoom the pattern. There is a bit agglomeration of some counts sticking out of the background at some places, but to my opinion nothing more than noise at the moment.
You should significantly increase the measurement time....
'can intensity .... mask...crystalline phases'; not the intensity of the background will do that, but it's noise. This noise of the background has to be smaller than your peaks you are aiming at. Also here: significant increase of measurement time (at least 10 times or even more).
Dear Denis Rodrigues ,
carbon has a quite low atomic number and thus has low x-ray attenuation. So I think carbon will not 'mask' crystalline material. This also holds for O, P and Mg.
As you already mentioned by yourself, I think you will accidently have picked up too less amount of the crystalline phase(s), if present at all in your sample.
'faintly' visible peaks? I do not see any one, even when I zoom the pattern. There is a bit agglomeration of some counts sticking out of the background at some places, but to my opinion nothing more than noise at the moment.
You should significantly increase the measurement time....
'can intensity .... mask...crystalline phases'; not the intensity of the background will do that, but it's noise. This noise of the background has to be smaller than your peaks you are aiming at. Also here: significant increase of measurement time (at least 10 times or even more).
Dear Denis Rodrigues ,
I fully agree with Dr. Gerhard Martens , and add one comment.
In case some semi-crystalline phase is intimated mixed with the amorphous, a razing angle experiment may give some additional evidence. It will probe a higher amount of sample per unit of sample holder area.
When such a mixture exists, the experiment gives some information. The background mainly caused by scattering at this condition would be lowered.
Perhaps it makes you sure of the points already pointed out.
Best regards
WNM
Dear Denis Rodrigues,
Carbon will not mask/(suppress) your crystalline material. If your material is crystalline and mix with amorphous phase, then you will get the XRD pattern as the sum of both the phases (crystalline and amorphous) (XRD pattern start with a hump then continue with crystalline peaks).
As there is no visible peaks (no faintly visible), nor perfect peak broadening to confirm the amorphous phase. You should repeat the measurement with low scan rate (long time).
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