Can we quantify the ratio of the constituent materials in a composite using powder XRD? For example, in a composite of CuO/ZnO, can I find the amount of CuO and ZnO in the CuO/ZnO composite?
Dear friend Dhanalakshmi Brammasuri if the peaks of the composite material are matched with the peaks of the constituent materials, then you can find the percentage composition of the constituent materials.
Then you can calculate the ratio of the constituent materials easily.
To determine the quantitative composition of the samples contained in a powder diffraction pattern you can do:
A) make a series of standard mixtures over the entire composition range, in your case CuO/ZnO from pure CuO to ZnO
B) Same with a fixed weight percentage of an external standard like Si, LaB6, Ceria
C) Run a full Rietveld type refinement with any of the available programs like Fullprof, Maud, GSAS, Topas.
For the analysis in A) and B) you can determine the integrated Bragg intensity of a single CuO and a single ZnO peak and compare their intensities to the normalized plot of the standards. This is a faster measurement, as you need less angular coverage but bears many pitfalls with preferred orientation, sample preparation etc.
Thus the best solution will always be a full Rietveld refinement. This has the additional advantage that you learn much more about the materials and that the differnce plot I(obs) -I(calc) readily shows if further phases are present in the sample.
As in any powder pattern make sure that a wide angular range is covered with very good intensity statistics, especially at high 2Theta. A noisy diffraction pattern is a waste of time and resource.
- Badges
- Science topic
- Similar topics
- Engineering
- Materials Engineering
- Coating