nano grains in opal

[jeolunlv12]

Hi, Group:

can anyone do EDS (WDS would be better) for nano size crystals (might be quartz or others based on Raman spectra) in opal?

we have a FESEM jeol6700F, but we do not have EDS on this tool.

any suggestion would be helpful.

Best,

Minghua Ren

Dept. of Geoscience,
UNLV

[Probeman]

Can anyone do EDS (WDS would be better) for nano size crystals (might be quartz or others based on Raman spectra) in opal?

We have a FESEM jeol6700F, but we do not have EDS on this tool.
Minghua Ren

Hi Minghua,
A FEG instrument is the right tool for this as you'll need to drop the beam energy as low as possible to minimize the electron interaction volume, but it depends on the elements you need...  I assume you are looking for trace elements?

You can use CalcZAF to model different electron interaction volumes for different beam energies in SiO2 from the Run | Calculate Electron and Xray Ranges menu.  But the overvoltages likely won't be enough, for say Fe, unless you utilize the La emission line.  There is an accuracy issue with L emissions but for trace levels it should be close enough given your likely precision.

[jeolunlv12]

Probeman:

thank you.

Minghua