Playing with Fi-- Liquid Nitrogen

Hello,

It would seem the temperature isn't about to settle down at any point in the next few days, as I've melted, frozen and melted again over the past week. And people mock when I say I don't know what to wear.

Wednesday was a day of preparation as there is the possibility of more of my samples undergoing x-ray diffraction over the weekend due to a low demand rapid access day (a day for quick sample testing and catch-up for those users who experiments have been blighted by beam problems). This did mean I was stuck in the lab most the day, preparing these samples, as I'm currently up to 7 samples of superconductor. And below you can see the kit I used to make the 8th.

The pestle and mortar used to mixed the salts. Before heating, they must be well grounded together to become a uniform clay-like colour. The white dishes are disposable weighboats used for the Copper Oxide and to the left you can see a toothbrush left over from capillary loading, since the same equipment is used.

Because of this, Thursday started the same and would have appeared to continue the same. This was particularly uncomfortable as the furnaces had not dipped below 200 degrees for over 36 hours by this point. It would seem I was responsible for the heatwave.

However, in the afternoon, my supervisor and the work experience student decided that it would be fun to play... I mean, seriously experiment with liquid nitrogen. So I left the baking lab to clearing ice off petri-dishes.

At first, we just tried to hover a magnet over a pre-made disk, which worked well of course. In some ways, it was inevitable that such high beginnings could not be carried through to my own experimental samples, since I had tried a variety of ways to make them, most which would never work.

Just as I was beginning to worry, though, there was a glimmer of hope as a small black slab I'd made supported a magnet! It wasn't as high as the professionally made piece, but I still call victory.

A view into the furnace, which glows red hot once above approximately 700 degrees. Any closer than that and I'd burn my fingers.

Friday was a day off as I was persuaded to go to London. ... Thankfully, my friend had a pool.

Monday was spent testing my samples with a new piece of kit... the SQUID (Superconducting QUantum Interference Device). This allows me to measure the magnetic moment whilst cooling and heating the samples from as low as 10K (-263 degrees) and varying the magnetic field. This provides a good idea as to whether I have superconducting material, giving a pretty graph to prove it. And do I? Well, early days, but the one superconductor I didn't try on Thursday (no. 8 was cooling still at that time) did look slightly promising... fingers crossed.

Type soon!