I am comparing crystallite size and strain using Scherrer and Williamson hall method.But I have doubt in mind whether the value of FWHM I am using is correct.
The Bragg peak width is a combination of instrument and sample dependent effects. To obtain correct peak width we need to separate instrumental broadening from the observed Bragg peak broadening. Thus, expressing in Gaussian distribution function
βd2 = βo2 - βi2
where βo = observed broadening and βi = instrumental broadening.Should I use βd value to calculate crystallite size and strain by Scherrer formula ? OR if it is something else please throw some light on the query?
please go to my RG page and select any paper concerns this issue and read it carefully.
Regards
Please Go to:
Article Improving microstructural properties and minimizing crystal ...
or
Article Synthesis, crystallography, microstructure, crystal defects,...
or any one
thanks
Here is one article for you
Article Microstructure and crystal imperfections of nanosized CdS x ...
Mr. Chandra Bhal SIngh I have (softcopy)book you are refering to ,kindly specify the chapter or page no. if you can thankyou.
Probably some of the papers referred to above will give you what you need to understand, but most introductory books like Cullity are too brief to take you beyond what you already know.
"Should I use βd value to calculate crystallite size..."
yes
"...and strain by Scherrer formula"
no, Scherrer gives no information on Strain.
Note, that the formula is only appropriate for Gaussian peaks
βd^2 = βo^2 - βi^2
On the other hand, if the peaks are Lorentzian, then the correct formula is
βd = βo - βi
The difference is because in reality the instrument and sample and other broadenings contribute to the observed peak as convolution. So to remove the instrumental effect correctly requires deconvolution. But that is hard so we subtract or subtract squared then take sqrt.
Note Cauchy is same as Lorentzian is same as Pearson VII with exponent = 1
And Gaussian is same as Pearson VII with infinite exponent (exponent > 10 is same as infinite in this context)
So when you use a Pearson VII with variable exponent, the appropriate exponent d in
βd^d = βo^d - βi^d
would be between 1 and 2
Dear Rishabh Sharma
Some books for X-ray application such as "Elements of X-Ray Diffraction " by B. D. Cullity are very usefull. However, in my published papers (powder technology and engineering fracture mechanic), not only i explained Williamson hall formula with its details to obtain crystallite size and strain but also i used Rietveld refinement technique. Details of my study is very useful for you. You can see them in my home page. the references in my published papers are also interesting.
Kind Regards
Dear Rishabh Sharma
Some books for X-ray application such as "Elements of X-Ray Diffraction " by B. D. Cullity are very usefull. However, in my published papers (powder technology and engineering fracture mechanic), not only i explained Williamson hall formula with its details to obtain crystallite size and strain but also i used Rietveld refinement technique. Details of my study is very useful for you. You can see them in my home page. the references in my published papers are also interesting.
Kind Regards
Dear Rishabh Sharma
Some books for X-ray application such as "Elements of X-Ray Diffraction " by B. D. Cullity are very usefull.
However, in my published papers (powder technology and engineering fracture mechanic), not only i explained Williamson hall formula with its details to obtain crystallite size and strain but also i used Rietveld refinement technique.
Details of my study is very useful for you. You can see them in my home page. the references in my published papers are also interesting.
Kind Regards
Dear Rishabh Sharma
Some books for X-ray application such as "Elements of X-Ray Diffraction " by B. D. Cullity are very usefull.
However, in my published papers (powder technology and engineering fracture mechanic), not only i explained Williamson hall formula with its details to obtain crystallite size and strain but also i used Rietveld refinement technique.
Details of my study is very useful for you. You can see them in my home page. the references in my published papers are also interesting.
Kind Regards
Dear Rishabh Sharma
In my published papers (powder technology and engineering fracture mechanic), not only i explained Williamson hall formula with its details to obtain crystallite size and strain but also i used Rietveld refinement technique.
Details of my study is very useful for you. You can see them in my home page. the references in my published papers are also interesting.
Kind Regards
Dear Rishabh Sharma
In my published papers (powder technology and engineering fracture mechanic), not only i explained Williamson hall formula with its details to obtain crystallite size and strain but also i used Rietveld refinement technique.
Details of my study is very useful for you. You can see them in my home page. the references in my published papers are also interesting.
Kind Regards
- Badges
- Science method
- Similar topics
- Methodology
- Crystallography
- X-ray Diffraction
- XRD Analysis