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Hi, everybody. My name is Ashley,

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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.

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So the majority of our equipment is housed in special research facilities.

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Some of these facilities include the nuclear magnetic resonance facilities and NMR, the electron spin resonance facility, ESR.

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We have chemical crystallography surface analysis and many, many more.

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All of these facilities are run by experts, and there's some of the most well-equipped in the country.

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And you're going to be treated to some fantastic podcasts from each of these facilities in turn over the course of this series.

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Just wanted to introduce where I work at the university, and that's the surface analysis facility.

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So I studied for my undergraduate degree and my Ph.D. in Surface Science and Catalysis at the University of Aberdeen in Scotland.

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And this is where I developed my interest in materials characterisation and surface analysis in particular,

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which has led me here to the University of Oxford,

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where I've had the chance to work with some fantastic scientists working at the very top level over three different chemistry buildings.

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So it's an absolutely massive chemistry department. I am so to introduce you to surfaces and why we study them.

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I am surfaces are important because they're the outermost part of the sample.

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It's the part where chemical reactions take place.

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So it's very important that we can quantify and characterise these surfaces because then we can make chemistry happen on them.

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Things that we might happen on a surface would be perhaps the adsorption of gas molecules

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onto a surface or catalytic reactions take place on the surface of a catalyst.

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So it's important that we can quantify this properly and properties that we're interested in.

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The surface and the kind of thing that we analyse routinely in our facility would be things like surface elemental composition,

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what makes up the sample and things like surface structure.

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So whether it's rough, whether it's smooth, whether there's holes in it and that kind of thing.

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So I just wanted to introduce you to the machine I probably use most regularly,

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which is called the the x ray two Electron Spectrometer, or XPS for short.

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I am with XPS, we can get a full elemental surface composition and that can be of absolutely anything.

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The only criteria being that it fits in the the big machine I am with an XPS.

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What we do is we fire X-rays at the surface of the sample.

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These x rays can penetrate down into the first few layers of the sample,

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and they transfer their energy to the electrons orbiting the atoms, making up your sample.

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And when it does this,

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this then gives the electrons enough energy to escape completely from the sample out into the the atmosphere and into the detector.

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This is known as the full electric effect, and these electrons emitted from the sample are called for two electrons.

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So once these electrons are in the detector, their energy is analysed by an analyser.

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And this energy can actually be related to particular elements.

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And this gives us a means of quantifying each element present in the area of the sample that we've analysed.

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We can also get a quantity of the element present from the number of electrons that have been that have been emitted.

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And this is very, very useful and it's a very well used technique in both industry and academia.

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The application of TSB's is just endless, and we use it regularly for both industrial and academic samples,

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and we do things like the quality control of thin films and coatings and paints and that kind of thing.

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We can have a look at the substrates that your paint sticks to.

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If it's not sticking, we can tell if it's because your surface is dirty, if it's contaminated, that kind of thing.

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We regularly analyse metal parts that failed.

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We can figure out why they feel that they've corroded if they've failed in some other way.

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The list is just absolutely endless.