A 2theta scan gives me peaks with Ni (Thin Film) and Fe (Substrate) at the same angle. I cannot observe or differentiate Ni peaks without studying samples at grazing angles.
Also, I prefer not to change the substrate.
Once again can I please state that there is no such thing as the Debye-Scherrer equation for this purpose. What you mean is the Scherrer equation. Debye had nothing to do with it. Debye-Scherrer is a type of diffractometer geometry, Debye-Scherrer scattering onto a photographic film, Debye-Scherrer analysis to determine lattice parameters from positions of rings on the film. It is not to do with crystallite size. It is a mistake that is getting everywhere, even into publications because people just copy without checking. Please everybody stop using it in this sense.
Generalisation of the Williamson-Hall method can be made in this case. However, great care has to be taken when considereing specific effects of the grazing incidence configuration, i.e. peaks shifting and experimental lines broadening. More details in:
Grazing incidence X-ray diffraction for the study of polycrystalline layers
Thin Solid Films, Volume 530, 1 March 2013, Pages 9-13
David Simeone, Gianguido Baldinozzi, Dominique Gosset, Sophie Le Caer, Jean-François Bérar
Dear Dr. Shri Ram, The crystallite size can be estimated from the Debye–Scherrer equation t= 0.9 λ/βcosθ where λ is the X-ray wavelength, is the full width at half maximum (FWHM) of the peak and θ is the Bragg’s angle.
Dr. Gossett, Thank you for your response and the paper you asked me to refer. I will go through that. Thanks again.
Mr. Kumar, Thanks for your response. Debye - Scherrer generally cannot be used in this situation as it depends on the FWHM of the peak and at a grazing angles, the x-ray peak tends to broaden.
It depend on the film, if it polycrystallin than GIXRD or IP-GIXRD even XRPD can use to calculate the size, but not for epitaxial film.
To use GI-XRD u need parallel beam configuration. U can calculate the penetration depth of ur sampleto get the rough estimation for the omega angle.
Dr. Manawan, Thanks for your response. Yes, my films are poly-crystalline. Studies were done at a parallel beam config. I might be able to use the debye formula to directly calculate the particle size then ?
Would you be able to cite a paper where GIXRD data was used to calculate the grain size in thin films?
Once again can I please state that there is no such thing as the Debye-Scherrer equation for this purpose. What you mean is the Scherrer equation. Debye had nothing to do with it. Debye-Scherrer is a type of diffractometer geometry, Debye-Scherrer scattering onto a photographic film, Debye-Scherrer analysis to determine lattice parameters from positions of rings on the film. It is not to do with crystallite size. It is a mistake that is getting everywhere, even into publications because people just copy without checking. Please everybody stop using it in this sense.
Dr. Slipper, Accepted, it was a mistake and its being made everywhere, not sure why. Sorry abt that.
I think by measuring the instrumental broadening using LaB6 and deducting that from the data obtained can help us get the right grain size at glancing angles. I can then use the scherrer formula to calculate the grain size. The Rigaku Smartlab software also has an option to deduce a grain size distribution curve (can calculate the instrumental broadening itself too).
Please permit me to ask one more question on this context: Can we assume that the avg. crystallite size size calculated from GIXRD (without compensating for low omega value) is always less than or equal to the real value?
Dear, Dr. Devesh Dadhich Shreeram, may I ask you, please, to what conclusion have you come finally?
You may choose either Williamson-Hall method or Debye–Scherrer equation t= 0.9 λ/βcosθ to calculate the average crystallite size.
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