Hello everyone,
In my experience, it is best to stay away from sulfate which has a hugely
intense peak subject to self absorption. At SSRL, we advice users to choose
Sodium Thiosulfate with the low lying and sharp S-S sigma star peak at
2472.02 eV and Tetraphenyl phosphonium bromide at 2146.96 eV
Hi Mike, Matthew,
On Thu, May 7, 2020 at 5:55 PM Mike Massey wrote:
> I agree Matthew, I also tend to use the primary K-edge peak for P
> calibration, but one issue to be wary of is attenuation/flattening of the
> primary peak (if one is using a concentrated sample).
>
> Gypsum sounds like a
Hello, all. It's been a long time since I've been in touch. Yes, energy
calibration is always an issue. Its especially important for lower-Z XAFS.
I feel that edge and transition energies should be recorded, but depending
on the beamline and facility the absolute calibrations are hard to
I agree Matthew, I also tend to use the primary K-edge peak for P calibration,
but one issue to be wary of is attenuation/flattening of the primary peak (if
one is using a concentrated sample).
Gypsum sounds like a good material to use for S, since it is commonly available
and probably not too
For elements like P and S, people often use the energies of peaks.
These are more immune to noise, energy-resolution effects and
overabsorption than inflection points are. For instance, on ALS 10.3.2,
I used the sulfate peak of gypsum set at 2482.74eV. I forget where I
got that number.
Hi Matt,
Indeed, in my experience (which is limited to one beamline at one synchrotron
facility for P XAS), once it is calibrated, the energy selection tends to be
quite stable, so I think you're on-target there.
The trouble I still run into, though, is comparability of data between studies.
Hi Mike,
On Tue, May 5, 2020 at 10:56 PM Mike Massey wrote:
> On a tangentially related topic, I find that phosphorus K-edge XAS energy
> calibration conventions are still in a bit of a "Wild West" state, with a
> wide variety of materials and values in use for energy calibration. As an
>
On a tangentially related topic, I find that phosphorus K-edge XAS energy
calibration conventions are still in a bit of a "Wild West" state, with a wide
variety of materials and values in use for energy calibration. As an extreme
example, one or two frequently cited papers in my field from the
All:
We are wondering if others agree that the reported values for the W L3 and W L2
edges are incorrect. We recently noticed the following:
The "Edge" - defined by the inflection point of the absorption edge step
When using the Ir L3 edge (11215.0 eV) as a calibration, the W L3- and L2-edges
This paper:
Kraft, S., Stümpel, J., Becker, P., & Kuetgens, U. (1996). High
resolution x‐ray absorption spectroscopy with absolute energy
calibration for the determination of absorption edge energies. Review of
Scientific Instruments, 67(3), 681-687.
has precision measurements of a bunch of
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