I want to calculate the average particle size of nanopowder synthesized from XRD but I want to know how can i get the FWHM (Full width at Half Maximum) values.
Dear Rather,
go to the site: http://pd.chem.ucl.ac.uk/pdnn/peaks/peakcon.htm
Do no forget that the obtained size of the particles is oriented according to the hkl indexation. Ex.: For layered compound if you take the 00L peak, only he thichness will be obtained. If you take the 110 peak, the size of the layered crystals along the a and b axis will be obtained.
There is no Debye-Scherrer formula but there is a Debye-Scherrer camera set up and a Scherrer formula.
Dear Mohd Yousuf Rather,
There is no way to find the FWHM from Debye- Scherrer formula, The are two ways to calculate the average size of the nanoparticles.
1.Modified Mie Theory.- From the absorbance spectra of nano particles, you will find out the FWHM in nm and it taken as resonance broadening(S-1). Using simple modified mie formula, you can calculate the average size. but the size obtain is approximation. if you want to calculate the size with certain accuracy, you fitting the absorbance spectra with data obtain from Mie Plot.
2. The average particle size of synthesized nano powder from XRD is also calculated using Debye-scherrer formula.
The FWHM of the peak of XRD spectra can be calculated using various data plotting software like sigma plot, origin, magic plot. The FWHM is the value of beta which is present in Debye- Scherrer formula, by putting the value of beta, the average size will be calculated
@ Jagdeep I repeat - there is no such thing as a 'Debye-Scherrer formula'.....
Dear Alan F Rawle,
The FWHM can be calculated from the XRD spectrum and it is taken as beta(used in expression) and then using Debye- Scherrer formula, the average size is obtained.
But i am also agree with you that from Debye- Scherrer formula, the FWHM cannot be calculated.
@ Jagdeep I repeat - there is no such thing as a 'Debye-Scherrer formula'.....
@ Abdul Seems that this was pointed out right at the start by a certain criminal called Alan F Rawle....
@Alan F Rawle. I am a learner and have quoted the term from the article attached here. In this article the authors has used the term " Debye- Scherrer formula" for which they have given three references as well. I was not able to find a way in calculating the FWHM, so I thought I will get help from here
https://arxiv.org/ftp/arxiv/papers/1003/1003.6068.pdf
Anyways thank you for your comments
Thank you Fernando Wypych and Jagdeep Singh for your suggestions.
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