I know the sharp peaks designate crystallinity. What does a broad peak or no peak or broad peak with sharp peaks on the surface of a broad peak mean?
Dear Bably Khatun ,
you are right;
a) the sharp peaks arise from diffraction at crystalline material contribution(s) (e.g. also called as crystalline phase(s)),
b) the broad peaks (e.g. those at around about 19° in 2theta) belong to 'diffraction' (or better elastic/coherent x-ray scatter) from the amorphous contribution (phase) to your sample, and
c) superposition of broad peak and sharp peaks indicate a co-existance of crystalline and amorphous phases present in your sample.
However in your case the little peaks on top of the broad ones indicate a quite small crystalline contribution (very low crystallinity) or even noise in your XRD pattern, which I think, they are due to, in most of the cases.
You should attach a count scale at your y-axis in order to be able to estimate the noise level (noise =sqrt(counts)).
Best regards
G.M.
Bably Khatun
Gerhard Martens always provides excellent substantive answers to which there's usually very little to add.
I would argue that one cannot 'simply interpret the XRD spectra' as you ask. There is no 'simple' answer in much of science unfortunately.
One needs to be familiar with the basics from a practical sense as well as a theoretical one. And this takes many years of study and experience in most cases - just as Gerhard Martens has...
Thanks Alan F Rawle ,
for the nice words...
I wish you, Alan, and all RG members a healthy and prosperous as well as a happy new year 2022.
Good luck to all of your families and you...
G.M.
I think @Gerhard Martens have answered your questions. From my practical experience, glass/quartz glass substrates introduce broad peaks about 20°. I guess you used glass/quartz glass substrates.
In addition to the answer of Martin C. Eze with respect to the amorphous background, I would like to add, that some hydrogels also peak around 20° and even down to 19°, as they do in some cases above. Bably Khatun , I think among others, you may deal with such kind materials. In contrast to them, water, which is present in many biological samples, peaks at about 27° in 2theta, having a broad shoulder at the decreasing right side.
However in the case of such broad amorphous peaks (also often called as 'humps') a unique identification of the amorphous material is in general often not possible.
Additional information on the sample type/material is required as well as details on the experiment (e.g. sample support, as mentioned above, and sample thickness) and/or sample preparation...
You may share the material names, which are hidden in the labels at your XRD pattern.
Its cyclodextrin curcumin complex and some are mixtures of other biopolymers as well@Gerhard Martens
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