Bleh cough cough

I have been a bit ill this week, so I missed a few days. I will now try to do them all at once.

On Friday I did some experiments on a sample I've been making for a while. I used Nice Little Microscope a.k.a. the 2010F, which is like the little microscope but bigger and better (wheelie chair included for scale):

Lots of buttons! And on the table is my lab book where I write down notes for every experiment I do so I can come back and check what I did later if I need to. Especially important if somebody gets a different result and needs to find out why.

This is what it looks like on the screen when you look at your sample:

That's the edge of my sample. (This is looking in through the the window at the front that is covered up in the picture of the microscope.) It is very very thin so the electrons can go through. The stripes at the edge are an effect of it getting thicker, like a beach. For the nerds: yes, I know it is out of focus. The material is made of quite light elements and the camera couldn't see the line on the screen when it was in focus.

What I wanted to find out with this sample, that somebody heated in a certain combination of gases, is whether there is a change in the number of oxygen atoms that are missing when you get to a boundary between two little crystals (grains). So I went to a boundary and (after a bit of faff) got an energy loss spectrum to compare with a normal bit of crystal. This is where you catch the electrons that came out the other side and measure how much energy they have lost from the energy you gave them at the start. That tells you what happened to them on the way through the crystal. In this particular material, if the features in a certain bit of the spectrum look more blurred, it's supposed to indicate more of the oxygen is missing. You get a graph like this:

It's pretty blurry but then it was a bit blurry in the normal bit too. So I have to do a bit more analysis on that before I figure out whether it's different or not. Then when I had done that I took a very high magnification image - LOOK, ATOMS!

That's on a TV screen that you can use to see more clearly than on the green screen. It's not quite atoms but it's a pattern the atoms make that is of the same size and orientation as themselves. I need to do some analysis on that pattern and see if it shows there are missing atoms or not, or if it in fact doesn't show anything one way or another, then I will have two different kinds of data to draw my conclusions from. (I also need to put a scale bar on it before I publish it anywhere!)

So that was Friday. At the weekend I decided the cough I had was not going away on its own, so on Monday I went to the doctor who agreed yes it might be a chest infection, so I have some antibiotics. Here is me pulling what is supposed to be a sad and slightly ill face but I look more like a surprised duck:

On Tuesday I was meant to be on the microscope again but I came in and it had burst a pipe and poured cooling water all over the floor, so I called Ian and we had to sort it out instead. Nothing broken in the end, just a lot of mess to clean up. So I am still iller than the microscope.

Today (Wednesday) I did some more sample prep on the samples I had been making last week. One of them was ready for the next step in the ion miller:

The sample goes inside through the airlock at the top and then the machine fires argon ions at it to mill away material really slowly and make it really thin like I showed in the microscope. You basically put the sample in, set it going for a few hours and just check it hasn't done something stupid every now and again.

Meanwhile a couple of other samples (the ones I had in the dimpler last week) were ready to be glued on supports so they will be ready for ion milling too, here they are on the messy lab bench:

After being trimmed slightly and cleaned with solvents, I use a little bit of super-pure glue (epoxy resin is ok for putting in an ultra high vacuum and zapping with an electron beam...the impurities in normal grade glue are not ok and will come off and make the inside of the microscope grubby) and stick the thin (not super-thin yet, just a bit thin) bits of material to little copper rings that will fit in the holders. They are under the glass lids to keep the dust off while the glue dries. The boxes on the top are just labels so I can tell them apart, one little round thing looks much like another!

So that is what I have been doing. Also coughing, and sleeping a lot :(

ps - The cats are safe! The fabulous Sheila and a team of super PhD students got together and adopted them properly, so now they are Our Cats. Yay cats!

Save our cats!

Today I have been preparing samples again...hopefully I will be able to show you the next big machine in the sample prep process tomorrow! If the glue on my samples manages to set overnight. I have mostly been trying to stick tiny bits of metal to 3mm copper discs using two pairs of very fine tweezers. Sometimes I am quite glad I spent so much time painting little pictures on my nails as a teenager.

In between bits of sample prep I have also been quite stressed because Estates management are planning to get rid of our campus cats! Here is the bravest cat, Taz, doing some important post-sorting duties:

Estates would like to remove Taz and shy Charlie from our campus because asthmatic people might be allergic to his fur. But there are lots of smokers outside the only entrance to the campus and they just stand there all day making smoke. And anyway if somebody doesn't want to sit next to the cat they just have to shoo him out and he will go somewhere else! So my office reckons they just don't think cats fit with the image of sterile, professional scientists doing Important Business.

But we scientists really like our cats. They are cute and fluffy and when we need to do some thinking or when we are stressed we go outside and give them some cat hugs - and then we come back in and do some really good science. In fact we should probably acknowledge our cats in some of the papers we write.

So we are slightly worried about our little cats today :(

Sample prep!

Back to work on Monday, and preparing some samples. This is the most boring part of my experiments but today is not so bad.

First I used the little old microscope and checked a sample I made last week to see if it was good enough to use. It was! This gives me an opportunity to show you the bits of an electron microscope:

My head comes up to the top of the yellow bit in the middle when I'm standing up, so it is fairly big. It fires electrons through the sample in a beam and we look at the picture the electrons make when they come through, just like a normal microscope except you use electrons instead of light, so you can see smaller things, e.g. actual atoms (cool). The sample has to be really thin for this to work, which is why you have to do a lot of sample prep, otherwise you can't see anything but the sample's shadow which is not much help. But the sample I finished this morning is thin enough, so I can go and use it later.

Then I worked on a different sample for a different project:

The little square-ish thing in the middle of all the circles is the actual sample. The dark blob is the material I want to look at, which is a powder, embedded in silver to hold it while I make it thin. The round bits are a stand for doing this:

The sample is now under the blue stuff which is a liquid containing tiny little bits of diamond (1 micron - a hundredth of a hair's breadth). There is a little wheel on that turns round and polishes down the sample using the tiny diamond bits, and the sample is turned round from underneath, and what comes out is eventually a bowl-shaped sample which is very thin in the middle. When it's so thin it's almost gone through, it's ready for the next method of making it thinner...hopefully I will show you that one next week.

Well hello! Welcome to Jo's science blog.

I will mostly make posts about the things I do from day to day as a scientist, especially the fun things. But to start with, here is my desk from last week:

From left to right:
-Window, looking out on the picturesque environs of the North Campus. If you follow the link and look at the Kroto Research Institute picture, my office is behind the tree and down in the basement. But the tree is gone now :(
-Bananas. Yum. Healthy.
-Computer where I have got some data open. This is a graph of the wavelengths of light emitted when you hit a sample with an electron beam, it is made of a lot of broad peaks from the different things in the sample like defects. I'm using the computer to find the positions of the peaks which tells me about the defects the sample had.
-Lunchbox. Should probably have thrown the crisp packet away before I took the photo but too dopey after lunch.
-Box of sweeties. Nuff said.
-Cup of tea, essential for science.
-Other computer where I am recording the peaks found by the other computer so I can analyse everything better. On top of this computer are a squillion nametags from different conferences, just in case I ever forget my name, I don't know why I keep those.
-Savlon
-Emergency teacups
-Hand cream

Just off the camera to the right is a big unholy mess of lab books, boxes of samples, "useful" bits of paper, etc. also vital to science.

So that is one of my scientist habitats. Next week, one of the other places I work, involving less food and more chemicals...