Meet the scientists!

My project is all about trying to understand mechanical properties of a common ceramic, called aluminium oxide. As ceramics are commonly brittle (you know that from practice – drop a ceramic mug on the floor, and you’ll know what I mean!), there is a lot of work being done to try and understand this, and then make them tougher. When a ceramic is put under stress, it can either start cracking, or undergo some “plastic deformation” (such as things called twins or dislocations). So, I am trying to use a microphone to listen to the sound of the ceramic breaking, and trying to work out when it starts to break/deforms. I then look at the sample in what is called a Transmission Electron Microscope (or a TEM) (see image) to try and find what sort of breaking/deformation has happened (see right hand image for example of this! This is what is called a “twin”. This is when the atoms rearrange themselves if a stress is applied. This is taken at 300, 000 times magnification. So these twins are around 0.00001mm across. Feel free to ask me about it!). With this work, we hope to have a better understanding of how these ceramics break, and so then we can work out a way to make them tougher!

There are other bits and pieces of my project which are related to this work – feel free to ask me about the work I am doing on the Focused Ion Beam (or FIB), the Scanning Electron Microscope (or SEM), the Optical Fluorescence Microscope (or OFM), or with cathodoluminescence! There is not enough space on here to describe all of these things, but I will answer all your questions if you are interested!

There isn’t really a typical day doing my PhD, which is the really nice thing. Every day seems to be different. I’ll normally get in at 8:20am, check my emails and Facebook, and then head to the lab. From then onwards, I could be doing any number of things. Sometimes I’ll be making samples to put in my compressing machine: I have to make a powder, then squash it into a little disc, then heat it in an oven at 1600C (which is pretty hot!). Once I’ve done that, I’ll cut it up, polish it, and then head over to the big compression machine (see image on left).

If I’m not doing that, I might be taking those compressed samples, and turning them into things that I can look at in the microscope. I have to get the samples really thin (0.1mm across), then we grind a small bump in the middle to make the centre really really thin (about 0.01mm across), and then we blast ions at it to make a small hole. This can then be looked at in the microscope.

Sometimes I am not in the lab during the day, but am teaching students or helping to run an open day for people your age. This means that I get to do fun experiments all day, such as making silly putty or using liquid nitrogen to make things float.

Although the department has a load of experiments that they run at Open Days (I help to run these experiments, and I promise you that they are good! See http://outreach.materials.ox.ac.uk/ ), there a few additional experiments that I would like to include, such as comparing the different mechanical properties (like, the strength, how much they stretch before they break) of different materials, like plastics, metals, bone etc.! Also, I would like to visit more schools in the Oxford area, and show them how exciting science can be. Not all schools can make it to our department to learn about science from us, so I think that we should be trying to get to the schools to talk to the students.

PS – If you are interested in coming to the department for an open day, let me know and I’ll put you in touch with the person in charge!