Taray,
For the case of samarium the optical
transmission spectrum shows good transmission from 500 to NIR. While the UV has
multiple sharp absorbance bands due to the 4f electron shell configuration.
Most of the rare earths show this behavior of sharp absorption lines. Note that
Neodymium Oxide has absorption past about 450nm giving the powder a blue
coloration while the Sm oxide is white.
The absorbance defines the color by the
reflection or absorbing of certain wavelengths of light. These absorbed
wavelength¡¯s can transfer their energy as heat or re-radiate it at a lower
wavelength called fluorescence. In the case of samarium note that it has a
strong absorbance at 401nm so by putting a strong laser in it at 405nm it can
be seen to fluoresce at 596 nm with smaller peaks at 558 and 594 nm.? In a
similar fashion illuminating it at the absorption line of 472 nm will produce
the same peaks with the amplitude will depending on the degree and bandwidth of
absorption.
?
In a similar fashion in XRF using
different HV setting and using filters at each voltage can change the
sensitivity to the element of interest.
In this Sm case the best response is from
beam #3 15 kV, followed by beam #2 40 kV, and then beam #1 50kV. Some setting
can miss things as you want the best x-ray flux close to and above (10-15 kev)
the elements binding energy¡¯s edge.
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If anyone wants to play with some REE
oxides I can send you some and RE minerals like cerite ,xenotime, monazite and
others work the same.
Dud KK7IF
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Some??people collect pure metals?
I notice??most??metals in a pure form tend to have a silvery??with different shades of grey appearance .
This??has something to do with electronic structure??related to absorption and reflection of visible light in pure
metals
Color??is a subject??familiar to UV and visible light spectroscopy.
One possible way to tell them apart
is??specific gravity which has been discussed before..
?Now back to xrf..
These are sample of??relatively pure??scandium,rhenium,dysprosium and samarium
To analyze peaks??results go to
?
One can??interpret any element of interest for xrf for free up to about 40
KV due to xray limitations.
Once there was a good free xrf software on
AppStore which covers a very broad??xrf range
Now it has been replaced by another paid
app??probably from the same seller.
Interestingly this XspecApp connects to
Dp5
I have no plans of purchasing yet
Poor ratings so far..
My samples are???barely a few gms (except??samarium??10 gms)and shot through a PE container?
Acquisition is only 3secs
?Xray 60 Kv 0.1 mA
Some of the peaks may be worthy of a
longer acquisition time.
The pics are from the seller website??for convenience.
Thanks
?
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On Monday, September 9, 2024, 9:31 PM, taray singh via groups.io
<sukhjez@...> wrote:
Info to follow next........
