Dear RG community,
I have analysed several flat sections of romanechite (Ba,H2O)2Mn5O10 by EPMA to have quantitative analyses. Romanechite would normally have about 15-17wt.% BaO but instead we have 2-3 wt.% BaO (see analysis bellow), which is a huge difference. We have rather the same results using EDS analysis of the same samples (4-5 wt.%Ba). Finally, when we did ICP-MS (whole rock sample of romanechite), the Ba content is "normal" with 14 wt.% (14,000 ppm) Ba.
I'm wondering why we have such a big upset when using EPMA. Maybe it is due to the standard (benitoite) we used or the ZAF calculation method. If you have any idea...
Thank you !
The standard:
Element Standard Mass(%) ZAF Fac. Z A F
BaO Benitoite 37.08 0.9158 1.0078 0.9087 1
Analysed romanechite:
No. SiO2 Al2O3 BaO As2O5 Fe2O3 MnO2 Na2O MgO CaO K2O PbO SrO ZnO WO3 CuO CoO Total
Sample1 0.051 0.358 2.854 0.123 0.232 62.265 0.01 0.004 0.2 0.02 0 0.166 0 1.937 0.078 0.089 68.387
Dear Augustin Dekoninck
Have a look:
1. https://www.degruyter.com/document/doi/10.2138/am-2019-6533/html
2. https://www.researchgate.net/publication/351456296_Reprint_of_Electron_probe_microanalysis_A_review_of_recent_developments_and_applications_in_materials_science_and_engineering
3. https://www.researchgate.net/publication/332381959_Quantitative_Measurement_of_Iron-Silicides_by_EPMA_Using_the_Fe_La_and_Lb_X-ray_Lines_A_New_Twist_to_an_Old_Approach
Best Regards
Dr. Fatemeh Khozaei
For what i can see, all the EMP analysis is bad.
Romanechite should show 0.5-1.0 wt% SiO2
MnO should be up to 68-70 wt%
In your analyses also these elements are underestimated.
Therefore I think it is matter of both quality of the section and wrong correction to standards.
cheers
Federico
- Badges
- Science method
- Similar topics
- Methodology
- Crystallography
- X-ray Diffraction