Cook Up Your Own High-Temperature Superconductors

It looks more like a charcoal briquette than anything, but the black brittle thing at the bottom of [Ben Krasnow]’s crucible is actually a superconducting ceramic that can levitate magnets when it’s sitting in liquid nitrogen. And with [Ben]’s help, you can make some too.

Superconductors that can work at the relatively high temperature of liquid nitrogen instead of ultracold liquid helium are pretty easy to come by commercially, so if you’re looking to just float a few magnets, it would be a lot easier to just hit eBay. But getting there is half the fun, and from the look of the energetic reaction in the video below, [Ben] had some fun with this. The superconductor in question here is a mix of yttrium, barium, and copper oxide that goes by the merciful acronym YBCO.

The easy way to make YBCO involves multiple rounds of pulverizing yttrium oxide, barium chloride carbonate, and copper oxide together and heating them in a furnace. That works, sort of, but [Ben] wanted more, so he performed a pyrophoric reaction instead. By boiling down an aqueous solution of the three components, a thick sludge results that eventually self-ignites in a spectacular way. The YBCO residue is cooked in a kiln with oxygen blowing over it, and the resulting puck has all the magical properties of superconductors. There’s a lot of detail in the video, and the experiments [Ben] does with his YBCO are pretty fascinating too.

Things are always interesting in [Ben Krasnow]’s life, and there seem to be few areas he’s not interested in. Of course we’ve seen his DIY CAT scanner, his ruby laser, and recently, his homemade photochromic glass.

16 thoughts on “Cook Up Your Own High-Temperature Superconductors

  1. The ferrofluid doesn’t work here because the earths gravity/magnetic field is nullified by the K delta (low vibration) of the substrate. Essentially, the substrate is vibrating at n which is a function of the magnets mass thus suspending the magnet in mid-air.

    This is essentially phase inversion, but the waves are gravity / magnetism.

    Since the inversion reduces the field, the ferrofluid has nothing to react to.

    1. The early 90 was the ht superconductor craze once that they only needed LN2 and every school wanted to show their students.
      If someone tried that today they would be shoot on sight for letting students closer than 1000ft of grinded Yttrium compounds.

      Now perovskitas is a buzz word again for high efficiency solar cells, but nobody is going to show it to any student.

  2. Barium carbonate, not barium chloride, and that reaction isn’t pyrophoric. No one seems to be pointing out how toxic barium and it’s salts are. What I’ve read suggests that slower cooling would produce a better product so hacking the controller might be worthwhile.

    BSCCO is a better superconductor in every way I know and might be a good choice for people not wanting to poison themselves or their environment.

    1. Corrected the barium salt in the text, thanks for pointing that out. But I think [Ben] is very clear on how toxic the fumes are, and it’s plain to see that he took adequate precautions. As for solid waste, I can’t speak to his disposal methods, but I’m pretty sure he’s conscientious about it.

      As for pyrophoricity, yeah, I see your point since that’s mostly reserved for the kind of reactions that metallic sodium and potassium undergo. But that’s what [Ben] called it, so I went with it.

    2. Good point. While the LD50 is kind of high (5 grams will kill a 70kg human), if you don’t follow proper PPE use and ingested it somehow you could feel sick with much less. If using this method you will want to pass the “fumes” through some kind of trap or at least a filter. Though I doubt you have gaseous barium you can easily get dust containing it.

  3. Very cool video, though I doubt I will be trying this soon, and even living in NY in the wintertime, I have a hard time wrapping my hear around -321 degrees Fahrenheit being high temperature.

  4. Hi, I am also working on this.
    As mentioned YBCO has the additional annoyance of barium getting you put on certain watch lists because not only is it toxic (it used to be used as rat poison) but Ba(OH)2 tends to form and muck up your hard earned work.

    BSCCO is tricky to make but all the “goodies” can be had from Ebay/etc and copper oxide is something that is feasible to not only make but test.
    the sort of problems you might run into are non availability of precision scales (see earlier comments) and temperature feedback: I solved all the problems but need more funding to even think about trying again.
    Have some samples left to compare with the new ones once its all working.

    Incidentally if you tried and failed to make YBCO it is possible to extract all the starting materials back out with some very simple chemistry but be damn careful PLEASE!
    Its an incredibly bad idea to try this in a kitchen but a garden shed with appropriate fume cupboard etc is (barely) acceptable if you at least let the authorities know what you’re doing and have the appropriate permits/training.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.