Hi, everybody. My name is Ashley,
and it is my pleasure to introduce this incredible machine series of the machines we have at the chemistry department at the University of Oxford.
So the majority of our equipment is housed in special research facilities.
Some of these facilities include the nuclear magnetic resonance facilities and NMR, the electron spin resonance facility, ESR.
We have chemical crystallography surface analysis and many, many more.
All of these facilities are run by experts, and there's some of the most well-equipped in the country.
And you're going to be treated to some fantastic podcasts from each of these facilities in turn over the course of this series.
Just wanted to introduce where I work at the university, and that's the surface analysis facility.
So I studied for my undergraduate degree and my Ph.D. in Surface Science and Catalysis at the University of Aberdeen in Scotland.
And this is where I developed my interest in materials characterisation and surface analysis in particular,
which has led me here to the University of Oxford,
where I've had the chance to work with some fantastic scientists working at the very top level over three different chemistry buildings.
So it's an absolutely massive chemistry department. I am so to introduce you to surfaces and why we study them.
I am surfaces are important because they're the outermost part of the sample.
It's the part where chemical reactions take place.
So it's very important that we can quantify and characterise these surfaces because then we can make chemistry happen on them.
Things that we might happen on a surface would be perhaps the adsorption of gas molecules
onto a surface or catalytic reactions take place on the surface of a catalyst.
So it's important that we can quantify this properly and properties that we're interested in.
The surface and the kind of thing that we analyse routinely in our facility would be things like surface elemental composition,
what makes up the sample and things like surface structure.
So whether it's rough, whether it's smooth, whether there's holes in it and that kind of thing.
So I just wanted to introduce you to the machine I probably use most regularly,
which is called the the x ray two Electron Spectrometer, or XPS for short.
I am with XPS, we can get a full elemental surface composition and that can be of absolutely anything.
The only criteria being that it fits in the the big machine I am with an XPS.
What we do is we fire X-rays at the surface of the sample.
These x rays can penetrate down into the first few layers of the sample,
and they transfer their energy to the electrons orbiting the atoms, making up your sample.
And when it does this,
this then gives the electrons enough energy to escape completely from the sample out into the the atmosphere and into the detector.
This is known as the full electric effect, and these electrons emitted from the sample are called for two electrons.
So once these electrons are in the detector, their energy is analysed by an analyser.
And this energy can actually be related to particular elements.
And this gives us a means of quantifying each element present in the area of the sample that we've analysed.
We can also get a quantity of the element present from the number of electrons that have been that have been emitted.
And this is very, very useful and it's a very well used technique in both industry and academia.
The application of TSB's is just endless, and we use it regularly for both industrial and academic samples,
and we do things like the quality control of thin films and coatings and paints and that kind of thing.
We can have a look at the substrates that your paint sticks to.
If it's not sticking, we can tell if it's because your surface is dirty, if it's contaminated, that kind of thing.
We regularly analyse metal parts that failed.
We can figure out why they feel that they've corroded if they've failed in some other way.
The list is just absolutely endless.