In the previous video I have shown the
use of XPS database, smoothing of a spectrum and energy calibration of an
element.Iif you have not watched it please check it now. The link is given in
the description. Now, I will show a quantitative analysis of the XPS
spectrum. Let's open it. In this spectrum, I will look for SiO2. I want to know the
quantitative presence of silicon and oxygen. Ideally the atomic percentage of
oxygen should be 66.66 and for silicon it should be 33.33. Let's find out how much percentage of each is present.
Now, I will open XPS database. XPS simplified DOT com If you can remember, I
have used this database in the previous video also. I am using it now to
understand the most commonly observed Core peaks of silicon and oxygen so that
I can easily identify them in my spectrum.
Let's see silicon first. It can have three peaks. 2p3/2,
2p1/2 and 1 indicating oxide and these are between 95 and 105 electron
volts. Now let's look for them in our spectrum.
Yes, these are the peaks we are looking for. I can confirm it once more. We can also confirm it from the elements library.
This is the elements library. The
smartness of this library is that, if you click on a position of the spectrum the
library will rearrange itself to show the information around that position
where you clicked. This one is 2p3/2 Next should be 2p1/2. We have difficulty to confirm the oxide peak. That's why you should use a
standard database or reported figure. Next step is, create a region, then name
it. Si 2p 3/2. Then enter. Adjust the region by
simply dragging the sidebar We need to create three components first one 2p3/2 Create another component 2p1/2. The position seems wrong.
It must be 102.5. Let's enter. The third one should be
here at ~116.37 and it is the oxide peak. Let's fit these components. Not very bad. Let's do the same for
oxygen peak. There are two peaks almost overlapping
and these are around 532. Let's create a region for oxygen peaks.
Adjusting the region. Name it. O 1 s Create the first component. O 1 s Interesting, here we don't need a second
one. Correcting the range of the region may
improve the fitting. Fit again. Let's see the result. To display the result, go to
annotation, then quantification, Choose components or regions. These are the atomic percentages for each component. Let's see the ratio of the regions. I have to delete one. To delete, go to
annotation history, select, delete the one you don't want. And here is the
result. The ideal was 33.33 and 66.66. We got around 34.5 and 65.5. Well it's not bad
for very initial trial.
However this can be improved. In the next videos, I will try to show how this can be improved. Stay tuned. See you in the next….