JEOL Probe Users Listserver

Moderator: Ellery Frahm, [log in to unmask],
Electron Microprobe Lab, University of Minnesota

Post a message: send your message to [log in to unmask]

Unsubscribe: send "SIGNOFF PROBEUSERS" to [log in to unmask]

On-line help and FAQ: http://probelab.geo.umn.edu/listserver.html



*

When using a any sort of raster (beam or stage) for quantitative 
analysis you also need to be aware that at the end of each line of the 
scanned area there is a finite dwell time before the next scan line is 
commenced.

In an inhomogeneous sample this will bias the results to the 
compositions of the periphery of the scanned area. Claims that the 
effect might be canceled out over several scans are of course untestable.




Ron Rasch wrote:
> JEOL Probe Users Listserver
> 
> Moderator: Ellery Frahm, [log in to unmask],
> Electron Microprobe Lab, University of Minnesota
> 
> Post a message: send your message to [log in to unmask]
> 
> Unsubscribe: send "SIGNOFF PROBEUSERS" to [log in to unmask]
> 
> On-line help and FAQ: http://probelab.geo.umn.edu/listserver.html
> 
> 
> 
> *
> 
> Hi,
> 
> this answer brings a question to my mind.
> When is it possible to do a quantitative analysis on a probe with a 
> rastered beam on an inhomogeneous sample?
> 
> I sometimes get asked this, but even though the software allows it, I 
> always say no. I assumed that the matrix correction for every point in 
> the raster will be based on the average x-ray intensity, yet this might 
> be different than the matrix correction required at a given point in an 
> inhomogeneous sample.
> 
> Have I missed something?
> 
> Thanks,
> Ron
> 
> 
> 
> ----------------------------------------------------------
> JEOL Probe Users Listserver
> 
> Moderator: Ellery Frahm, [log in to unmask],
> Electron Microprobe Lab, University of Minnesota
> 
> Post a message: send your message to [log in to unmask]
> 
> Unsubscribe: send "SIGNOFF PROBEUSERS" to [log in to unmask]
> 
> On-line help and FAQ: http://probelab.geo.umn.edu/listserver.html
> 
> 
> 
> *
> 
> Most of the samples we receive are of this type (Platinum-Aluminide 
> coatings
> of engine parts).  I use pure element standards and have pretty good
> success. The difficulty is that the material is very inhomogeneous and the
> customer usually wants an average composition. They require analyses with a
> beam raster over a certain area of the coating. I usually have a set of
> about 10-12 elements in the analysis.
> 
> Chuck Herrington
> Geller MicroÅnalytical Lab, Inc.
> 978-887-7000
> [log in to unmask]
> 
> 
>   _____
> 
> From: JEOL-Focused Probe Users List [mailto:[log in to unmask]] On
> Behalf Of Ellery Frahm
> Sent: Wednesday, April 04, 2007 12:01 PM
> To: [log in to unmask]
> Subject: [PROBE-USERS] Ni-Pt-Al standard?
> 
> 
> JEOL Probe Users Listserver
> 
> Moderator: Ellery Frahm, [log in to unmask], Electron Microprobe Lab,
> University of Minnesota
> 
> 
> Post a message: send your message to [log in to unmask]
> 
> 
> Unsubscribe: send "SIGNOFF PROBEUSERS" to [log in to unmask]
> 
> 
> On-line help and FAQ: http://probelab.geo.umn.edu/listserver.html
> 
> 
> 
> 
> * Probe folks,
> 
> 
> I have a post-doc researcher here in one of our engineering departments who
> is interested in analyzing a Ni-Pt-Al system. I've been trying pure metals
> as standards for his samples, but obviously I'd like to minimize any
> absorption or fluorescence issues there might be. Does anyone have any
> experience with such a system? Do you know of suitable standards for such a
> system, or have you just used pure metals?
> 
> Thanks,
> Ellery
> 
> --------------------
> 
> Ellery E. Frahm
> 
> Research Fellow & Manager
> 
> Electron Microprobe Laboratory
> 
> University of Minnesota - Twin Cities
> 
> Department of Geology & Geophysics
> 
> Lab Website: http://probelab.geo.umn.edu
> 
> Personal Website: http://umn.edu/~frah0010

-- 
[log in to unmask]
DEPARTMENT OF EARTH SCIENCES
UNIVERSITY OF CAMBRIDGE         Tel +44 1223 333469
DOWNING STREET                                 +44 1223 333400
CAMBRIDGE                                    FAX +44 1223 333450
CB2 3EQ

Manager of XRD discussion list:
http://www.jiscmail.ac.uk/lists/xrd.html

VirtualWDS: For the synthesis of wavelength-dispersive electron probe 
spectra.  http://www.esc.cam.ac.uk/astaff/buckley/VirtualWDS.html