I fabricated the TiO2 thin film of 500 nm on glass substrate using dc sputtering method. Now i want to find out the dislocation density in this thin film.
Use the XRD data, to determine the crystallite size (D) from the full width at half maximum (FWHM) using Scherrer equation then determine the dislocation density (𝛿) according to the relation:
𝛿 =1/𝐷2
Best regards
Use the XRD data, to determine the crystallite size (D) from the full width at half maximum (FWHM) using Scherrer equation then determine the dislocation density (𝛿) according to the relation:
𝛿 =1/𝐷2
Best regards
in line with Dr Mohammed answer, you can use the attached PPT file regarding determining the crystal size and using the equation.
I think XRD will only work if the dislocation density is pretty low. If it is high, you can have several dislocations per grain or crystallite and then the approach via the Debye-Scherrer method won't work any more. Otherwise the MIT power point slides by Scott Speakman are great!
1. The Scherrer equation uses the "integrated breadth", Beta, in Radians and not the FWHM. In order to use the FWHM instead of Beta, one must assume a shape to the Bragg profile and then convert the FWHM value to the correstponding Beta (integrated breadth) value in Radians. Then apply the Scherrer or other emperical relations to estimate various corelation lengths.
Integrated breath squared, Beta2, may be related to the "defect density" through the Burgers Vector. Hersh eta all.
2. Have you recorded XRD profile from this specimen yet? Post it.
3. Have you recorded the XRR, X-ray reflectivity, signal for this sample yet? Post it.
4. What is your proposed (hypothesized) model of the film and substrate?
- Amorphoous substrate?
- Polycrystalline film?
- Expected grain, particle, and/or diffracting domain (crystalliet) size?
- Presence of preferred orientaion?
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