Sciencemadness Discussion Board

Making my own superconductor (MgB2)

MrMario - 2-6-2016 at 06:44

Hello Sciencemadness users,

I have become very interested in superconductors since they have really cool properties I want to explore further. I want to make my own MgB2 superconductor if that is possible from Mg and B. Since most demo's use very small super conductors I want to make one big super conductor with much greater field strength and a larger repelling distance.

Would it work if I were to melt Mg and B in a DIY propane furnace and pour it into a mould? It also seems that coating some superconductors with carbon seems to increase the upper critical field.

From wiki:
Quote:

"Various means of doping MgB2 with carbon (e.g. using 10% malic acid) can improve the upper critical field and the maximum current density[11][12] (also with polyvinyl acetate[13]). 5% doping with carbon can raise Hc2 from 16 T to 36 T whilst lowering Tc only from 39 K to 34 K. The maximum critical current (Jc) is reduced, but doping with TiB2 can reduce the decrease.[14] (Doping MgB2 with Ti is patented.[15]) The maximum critical current (Jc) in magnetic field is enhanced greatly (approx double at 4.2 K) by doping with ZrB2.[16] Even small amounts of doping lead both bands into the type II regime and so no semi-Meissner state may be expected.


If anyone here has experience with making their own super conductors I'm glad to hear their story/tips/tricks.

My future hobby resolutions:
-Build a big ass superconductor
-Find out if it is possible to increase the magnetic levitation field with electrical input?
-Get liquid nitrogen or helium (this will be ofcourse a lot harder)

How cool would it be to have a gigantic super conductor with a repelling radius of for example 1m? If there is one thing i want to create as a crazy scientist this would be it. Maybe standing in the field will deflect time, who knows :D?

Cheers!

elementcollector1 - 2-6-2016 at 08:29

Not really how superconductors work, but hey, gotta love ambition. If I had to guess, your MgB2 would best be created by reacting boron and magnesium powder together in an inert atmosphere (MgB2 burns in oxygen) and sintering the result.

Electrical input will only increase magnetic output if the superconductor is formed into a tape and wound as an electromagnet. Because this electromagnet has no electrical resistance, it can carry and maintain much higher currents than conventional electromagnets.

But why not use yttrium barium cuprate? It's easier to work with, and probably has a higher critical temperature, unless I'm out of the loop on superconductor developments.

For the liquid nitrogen, I might suggest a Joule-Thomson cooler (unsure if I spelled that right). They're very slow, but very cheap and run on limited power (5-100 mW).

unionised - 2-6-2016 at 11:11

Both B and Mg are rather reactive- what do you plan to melt them in?

deltaH - 2-6-2016 at 21:44

I haven't checked the thermodynamics of it, but maybe investigate if you can make a boron oxide/magnesium thermite with the correct stoichiometry, as a way to prepare the crude powder. The magnesium oxide that would be co-formed can easily be washed away in very dilute acid should the reaction work. Then I would press the magnesium diboride under high pressure and sinter in a kiln.

? 4Mg + B2O3 => MgB2 + 3MgO ?

Only problem is magnesium's low boiling point 1091 °C

[Edited on 3-6-2016 by deltaH]