I fabricated a composite say AB and both are carbides ceramics having formula AC and BC. I did EDX point analysis and observed A (45 wt %) and B (28 wt %), Carbon (26 wt %) and Oxygen (1 wt %). Can this data confirms the formation of A rich (A, B) C solid solution? Also at one location I got Carbon (83 wt % ), Oxygen (16 wt %), A (1.62 %) and B (0.13 %). Does that means precipitation of carbon at grain boundaries ? In EDS elemental mapping for some composition both element A and B mapping are superimposing at most of the places. Does it means formation of a intermetallic compound AB or it may be (A, B) C solid solution ?
In addition to EDS you need to study microstructure to see if you really have a single phase specimen. BSE imaging and/or etching should help, If you want to quantify light elements (O, C) you need standards, standardless analysis is not reliable.
Article XRD, EDX and IR Analysis of Solid Solutions Between Thaumasi...
EDAX sometimes provides highly localized data, compared to average bulk information. Detailed crystallographic analysis, Rietveld refinement and XPS-UPS measurements are better alternatives.
Regarding the weight percentages, you have provided, it hints that, probably your desired solid state solution has synthesized, but it does not guarantee the same.
For a more efficient analysis, you could acquire EDAX data at multiple locations, compare them and take their average. If the weight proportions are close, then the solid solution is quite uniform. But, very often due to some residual precursors, local weight proportions vary drastically.
Basically, crystallographic analysis are best for phase matching, which may be accompanied by FTIR, Raman spectra, absorption spectra, XPS etc. EDAX is just a tool to calculate atomic proportions. It has another disadvantage: it cannot differentiate different polymorphs, having same formula.
In addition to EDS you need to study microstructure to see if you really have a single phase specimen. BSE imaging and/or etching should help, If you want to quantify light elements (O, C) you need standards, standardless analysis is not reliable.
Thank you for the info Dr. Azeez and for clarification Dear Souvik and Vladimir. It would be very helpful if you make any conclusion with this SEM image of the unetched composite taken in SE and BSE mode ? Also after the XRD analysis of sintered samples some peaks related to A are missing. Can this be related to the fact that A dissolves in B and forms solid solution during sintering ? Vladimir Dusevich
Are you sure you did not mislabeled pictures? For me the upper one looks like BSE.
Vladimir Dusevich Yes m sure, the upper image is SE image while the lower one is BSE image.
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