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closeEDS Question
Posted by metalguy on 05 Mar 2012 at 20:05 GMT
Can you confirm and explain the presence of strontium in your EDS spectrum?
I see peak labels for Fe, but no definable peaks. What elemental peak is present between the missing Fe peaks?
Also, can you explain the high Ca peak shown to the left of the C peak? What is your low energy cut off and does your system generate a 0 energy pulse for calibration?
RE: EDS Question
PWeaver replied to metalguy on 06 Mar 2012 at 17:21 GMT
I will be happy to answer your questions, but I hope you won't mind waiting for a few days. I'm on some deadlines at work.
RE: RE: EDS Question
metalguy replied to PWeaver on 23 Mar 2012 at 17:02 GMT
Were you able to contact the analyst to address my questions?
RE: RE: RE: EDS Question
PWeaver replied to metalguy on 27 Mar 2012 at 14:08 GMT
Sorry for the delay, we are opening a new wing at my institution and getting a moment to re-examine our data was problematic. To answer your questions: Yes strontium is present in our sample. Strontium commonly substitutes for calcium in aragonitic shells and is usually an indicator of temperature.
From looking at our spectrum there are two iron peaks K alpha and K beta the larger K alpha peak is the one you are seeing in between the labels. The K alpha label is slightly skewed to the left of the actual peak. Something we did not notice.
The large calcium peak to the left of the carbon peak represents the absorbance edge for the detector. The SEM we were using labeled that edge as calcium. This is in error. There should be no label for that peak, it is not calcium.
I don't have the machine specifications for the SEM we used, but I can get at them if you would like me to. Again Sorry for the delay, I hope my response answers your questions. Please post again if you have further questions.