Sciencemadness Discussion Board

MgB2 compared to NbSn3

Jackson - 4-12-2018 at 07:59

I am trying to determine what superconductor I should use for a project. I am making my own wires and materials so I have some questions about viability of each conductor. For the NbSn3 I would either coat a Niobium wire with tin and heat to form a coating of NbSn3 or I would mix tin and niobium metals together to make NbSn3, powder the mix, pack into a metal tube, heat, extrude using a wire rolling mil, and heat againl. For the MgB2 I would mix Magnesium with Boron and heat under an inert atmosphere at 800-1000 CĀ°. I would then powder it, pack into a copper or silver tube, heat, extrude using a roller mill, and heat again. Niobium and tin are relatively expensive, and I do not have any experience in electroplating to plate the tin onto the niobium. Boron and magnesium is cheaper and I already have magnesium. I can make the boron using the process of:
Na2B4O7 + HCl + H2O ā€”> H3BO3 ā€”> BO3 + Mg ā€”> B
MgB2 has a higher critical field than NbSn3 and can be cooled for cheaper than NbSn3.

Are there any details i am not accounting for?

12thealchemist - 4-12-2018 at 08:39

I suspect it would be easier to form the intermetallic NbSn3 than MgB2 given boron's tendency to form many mixtures of B-B bonded species, for example the hexaboride. Synthesising pure MgB2 could be a challenge, despite the reduced cost.

clearly_not_atara - 4-12-2018 at 21:23

I remember that once I asked a researcher who works with large superconducting magnets why NbSn3 is preferred over MgB2. He said that the former compound is much more ductile and easy to work with while MgB2 does not form wires easily.

trace impurities can strongly affect the properties of a superconductor. Synthesizing the pure material is important.

ninhydric1 - 4-12-2018 at 22:00

Niobium can be easily bought on Ebay as well, so making NbSn3 is probably a lot simpler than attempting to purify the various side products that might arise from the Mg + B reaction.

Jackson - 5-12-2018 at 10:05

It sounds like I will probably go with NbSn3 due to it sounding like its easier to make successfully as compared to MgB2. Should I use a powder in tube method or should I make films of tin on Niobium wire and heat to cause diffusion of the tin into the niobium?

Jackson - 5-12-2018 at 10:35

Another process is one where a bronze made of tin copper and niobium is draw into wires, wound into the desired shape, and heat treated to form the Nb3Sn. I dont know if this is more viable or not but it seems like it could work.