I have found somewhere the formula for the average crystalline size as follows
i.e Debye-Scherrer formula
L = (0.89*lambda)/beta*Cos(theta)
L = average crystalline size (nm)
lambda = X-ray wavelength
beta = FWHM
theta = Bragg angle of the plane
Is this itself gives the grain size?
are average crystalline size and grain size same or different?
If different, what is the formula to calculate grain size?
Thank you in advance for your replies
Please see the answer of a similar question on RG and grain/crystallite size aspects of a question some days ago and attachments therein. May be helpful to you.
https://www.researchgate.net/post/Is_there_any_relation_between_FWHM_of_XRD_pattern_and_grain_size_of_the_thin_film
Hi,
No, from Debye-Scherrer formula you can't get the grain size, it will give the crystalline size.
Crystalline size and grain size both are different. Crystalline size is refers to the size of a single crystal inside a grain. A single grain can be composed of several crystals.
To get the grain size it will better to do microscopic spectroscopy (like TEM, SEM, etc.).
Regards
Bapi
Thank you Bapi Ji,
Well. I have done SEM imaging and EDX for the same sample. Can you please explain me how to calculate the grain size from the SEM data.
Hello,
Best answer from RG : The simplest techniques to estimate an average grain size is the intercept technique. A random straight line is drawn though the micrograph. The number of grain boundaries intersecting the line are counted. The average grain size is found by dividing the number of intersections by the actual line length.
Average grain size =1/(number of intersections/actual length of the line).
where actual line length = measured length divided by magnification.
You can watch youtube video from the below link.
https://www.youtube.com/watch?v=aHHJvgrutec
Regards
Bapi
I think this link can help you out sir
http://www.instanano.com/characterization/theoretical/xrd-size-calculation/
Bommareddy Poojitha
In this and some other videos, I have explained what is a crystallite, a grain and a particle, and how to calculate it from XRD data. You may comment on the same video if you have further to ask. Thanks
https://youtu.be/lZ1VESKBxKY
Please note that the XRD method may not be effective for sizes larger than 1 um. It's important to verify this before attempting to apply the method. Please refer to the following source for further information.
Article Method for Determining Crystal Grain Size by X-Ray Diffraction
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Inorganic Materials
- Metals
- Alloys
- Steel