Home-made superconductors ?

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Is it possibly to make a superconductor at home ? I mean with limited funds and ... you know. Maybe this idea is a bit crazy but I'd like to know. :biggrin:
 

Gokul43201

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Here's a few problems :

1. Even the reasonably high Tc superconductors (HTSCs) need close to liquid nitrogen (LN2)temperatures to be superconducting - so need need to buy LN2 everytime you want to do a demo or "use" your HTSC. This is not so hard, and not especially expensive, either.

2. One of the easier HTSC to make is YBa2Cu3O7. To make this you need to start with the oxides/carbonates of yttrium, barium and copper. These are often hard to get unless you work for a research lab.

3. The mixture of the oxides needs to be sintered in a furnace at fairly high (nearly 2000F) and well controlled tempertures and media. So you need a furnace with oxygen flow . Recently, however, people have been able to replace a conventional furnace with a standard 600W microwave oven modified to allow oxygen flow and let in a thermocouple probe to measure temperatures.

4. Even under laboratory conditions, this is tricky and often does not work. The reaction chemistry is complex. YBCO itself is only a metastable phase at high temperatures. In other words this is a "little" hard and possibly dangerous, if you have no experience with such things. However, access to a university lab would make things a whole lot easier.

Disclaimer : The last that I worked on synthesis of HTSCs was about 6 or 7 years ago. Things may have changed a lot since then that I know nothing about. You should wait for more inputs on this before you make up your mind. There may just be a "Make your own superconductor" kit selling at Toys'R'us, for all I know.
 
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Gokul43201

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Check out http://www.chemsoc.org/exemplarchem/entries/igrant/making_noflash.html [Broken]

They seem to suggest that it may not be too hard.
 
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Thanks a lot, but what about low-temperature superconductors ? Are they easier whether harder to make ?
 

Gokul43201

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Most ordinary metals ARE low temperature superconductors, so there's no making required. But that's going down to liquid helium temperatures.

What is this in aid of ? Is there a larger picture that might help us understand what you want ?
 

ZapperZ

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Initially, I did not want to respond to this question because it makes no sense. Why would anyone want to MAKE lead (Pb) at home, for example, when you can easily buy one from a hardware store? Then someone described a "process" in making a cuprate superconductor and that's when I should step in. I would HIGHLY recommend that you do NOT even attempt to make such compounds. ALL the high-Tc cuprates consist of at least ONE extremely toxic element (Y, Ba, Tl, Hg, etc). Besides the fact that I hope you do not have the lawful ability to get one of those chemicals, these things can kill you very easily. I also doubt that you have a high temperature furnace available in your home to synthesize the parent compound of these materials, much less to anneal it to get the optimum doping content.

Zz.
 

Gokul43201

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ZapperZ said:
I would HIGHLY recommend that you do NOT even attempt to make such compounds. ALL the high-Tc cuprates consist of at least ONE extremely toxic element (Y, Ba, Tl, Hg, etc).
Reminds me of the theory that states that "the Tc of a superconductor is directly proportional to the number of toxic elements in it !!"

But in all seriousness, you should heed Zapperz' warning. I recall mentioning that this was possibly dangerous. Perhaps I should delete the "possibly". When I said it's hard to come by stuff like Yttrium oxide, I didn't say why...now you know !

However, I don't think it's as hard to get the doping levels right. This is just a matter of correctly calculating weight ratios and having a fairly sensitive balance.
 

ZapperZ

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Gokul43201 said:
However, I don't think it's as hard to get the doping levels right. This is just a matter of correctly calculating weight ratios and having a fairly sensitive balance.
No, I don't mean the doping level in terms of the proportions of the various elements. I mean the "hole doping" content. When you synthesized the cuprate out of the furnace, you first make the insulating parent compound (the Mott insulator). This isn't a superconductor (it isn't even a "good" conductor). For hole doped cuprates, you have to anneal it in oxygen just with the right pressure, and length of time, to get it to optimum doping where Tc is the highest. If you annealed it too little, you are underdoped and you run into the pseudogap states and encounter a bunch of issues. If you annealed it too much, you overdoped the material and Tc drops again (my avatar is the ARPES spectra of a highly overdoped Bi2212 cuprate).

So "doping" here is the hole content (or electron content for electron-doped cuprates).

Zz.
 
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Thanks for all your answers. It is just curiosity at the moment, however soon I'm going to change my school (going to high school, y'know :biggrin: ) and if my dreams come true I'll have everything I'd ever want.
 

Gokul43201

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ZapperZ said:
No, I don't mean the doping level in terms of the proportions of the various elements. I mean the "hole doping" content. When you synthesized the cuprate out of the furnace, you first make the insulating parent compound (the Mott insulator). This isn't a superconductor (it isn't even a "good" conductor). For hole doped cuprates, you have to anneal it in oxygen just with the right pressure, and length of time, to get it to optimum doping where Tc is the highest. If you annealed it too little, you are underdoped and you run into the pseudogap states and encounter a bunch of issues. If you annealed it too much, you overdoped the material and Tc drops again (my avatar is the ARPES spectra of a highly overdoped Bi2212 cuprate).

So "doping" here is the hole content (or electron content for electron-doped cuprates).

Zz.
Mostly, the hole concenration is a function of anneal time and temperature - you can make YBCO at 1 atm. fairly easily. This IS the part that I refered to as tricky, before. Still, I know a bunch of high school and undergrad students that made YBCO simply by following a recipe. And something like one out of every 7 or 8 pellets was able to levitate over an NdFeB magnet.

The link provided by sol2 lists Superconductor kits. I don't know what these include but my guess would be that they have the SC pellets themselves along with a hard magnet and perhaps a LN2 flask.
 

arivero

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First course chemistry in the UAM (Madrid) did YbaCuO as an exersise. Good teacher (now in the UCM)
 

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