Well no need to separate them from their backing plate. Actually I'm after the rare earth metals that are used to make the things, because theres something I've been wanting to try, called adiabatic nuclear demagnetization, this is where certain metal alloys that exhibit a very high magnetocaloric effect, or paramagnetic mineral salts can be introduced to a reasonably powerful magnetic field (IIRC the lower threshold is somewhere in the region of 2 Tesla, allowed to heat up, cooled down whilst in the magnetic field, and then moved to an adiabatic environment, then slowly demagnetized.
The result is a powerful cooling effect. It seems paradoxical, but it works by taking advantage of entropy level limitations, whilst removing entropy from the system and disallowing it to increase, so when the magnetic flux ceases and the magnetocaloric alloy/paramagnetic salt is isolated from the rest of the environment, it cools down, and very strongly too. With sufficient magnetic flux strength and proper cooling, the system is capable of reaching temperatures a fraction of a degree kelvin above absolute zero. Now don't get me wrong, I'd not be at all unhappy with a simply decent cryostat, but being able to produce my own liquid nitrogen, liquid oxygen via fractional distillation of air, and liquify pre-dried chlorine gas for storage in cylinders, so as to allow me to simply turn on a tap when I want Cl2 rather than fuck about with gas generators, electrolysis etc. and have to run the result through drying tubes, as well as store anhydrous ammonia and liqufied SO2, nitric oxide, nitrogen dioxide, nitrous oxide and N2O4..
