Undergrad labs

Solid State Synthesis of YBCO

This little video came from the final day of the first year undergraduate experiment at UCL chemistry.  The student mixes the components of a very interesting solid state material known as YBCO. The powders are ground thoroughly before being pressed into a pellet. Once the pellets have been fired at 800 ºC the pellets are returned to the students where they get to see if their pellets are superconductors.  The experiment is used to discuss the concept of the Misner Effect and how perfect diamagnetic materials occur.

Points for consideration

  • The superconductor is the black disk and the magnet is what is being suspended.
  • The smoke is Liquid nitrogen boiling off. this keeps the system below the curie temperature Tc.
  • The coins are there as a heat sink to slow down the process of heating that raises the temperature above the Tc.
  • Normally this demo is done in a basin of liquid Nitrogen so is far easier to keep cold.
  • The system reaches a temperature and the sudden heating kills the superconducting at the end of the vid where the magnet then falls.

Cobalt Experiment. Thermodynamic v.s. Kinetic Stability

Cringe!! This is the intro talk for the experiment.  It is very interesting to video ones performance so you can see exactly how you were and look to improve yourself. I do this not because any directive has made me but because it is interesting for my own professional development.  I put it up here to show what i am like teaching.  Never particularly nice to see yourself on film..

Points for consideration

  • I think the students are just a little shy rather than not knowing the answers!!
  • For those that noticed the mistake… The ligand is actually a NO2- and not a NO2+.  My bad I don’t know why it came out that way..