Why do we need Reitvel refinement only for powder samples? Can it be used for 1.5 micrometer thick polycrystalline film? If it is necessary for thin films, what information can I extract from it?
Hi! Rietveld analysis is a program to filter your lattice parameters via d-value and the actual intensity of a particular phase or plane can be theoretically estimated. This gives you very accurate d, lattice parameters (a, b, c) and other parameter. So, strain of your sample, crystallinity, calculated Intensity, quantative analysis (% W, of elements, phases) etc. can be calculated. For thin film sample it is difficult.
I cannot be sure about thin films, but Rietweld refinement for any structure can give you the lattice parameters and atom locations refined/ This depends on whether you obtain good diffractograms
Rietveld refinement for thin films are generally not carried out as the refinement includes the intensity of all the reflections of a given compound. In films, either we see few peaks of the compound and the substrate peaks. For powders, it is quite essential as it gives the structure, local coordination and bond distances and angles.
Hi! Rietveld analysis is a program to filter your lattice parameters via d-value and the actual intensity of a particular phase or plane can be theoretically estimated. This gives you very accurate d, lattice parameters (a, b, c) and other parameter. So, strain of your sample, crystallinity, calculated Intensity, quantative analysis (% W, of elements, phases) etc. can be calculated. For thin film sample it is difficult.
It is essential to perform high intensity scans for refinement purposes. In addition, experimental errors and other errors need to be eliminated. One such factor, I guess, is the preferred orientation in thin-films grown or deposited on substrates. The substrate may also show additional peaks in the scans when reflecting-parafocusing mode of Bragg-Brentano setup is used. Alternative modes of measurements will require further attention and may lead to low-intensity scans (for very thin films) that may result into less accurate refinement process. However, you may try to find solutions to these shortcomings because diffraction requires few atomic layers of any crystalline structure and one should know how to collect the diffracted rays.
Ahmed 's suggestion is quite impressive. In that case one can scan the thin film for longer duration, I mean slow scan with high power of source ( allowed max. KV and max.mA) to get good counts
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