Room Temperature Superconductor? Yes, But Not So Fast…

There’s good news and there’s bad news in what we’re about to tell you. The good news is that a team of physicists has found a blend of hydrogen, carbon, and sulfur that exhibit superconductivity at 59F. Exciting, right? The bad news is that it only works when being crushed between two diamonds at pressures approaching that of the Earth’s core. For perspective, the bottom of the Marianas trench is about 1,000 atmospheres, while the superconductor needs 2.6 million atmospheres of pressure.

Granted, 59F is a bit chilly, but it is easy to imagine cooling something down that much if you could harness superconductivity. We cool off CPUs all the time. However, unless there’s a breakthrough that allows the material to operate under at least reasonable pressures, this isn’t going to change much outside of a laboratory.

The top temperature for superconductors has been rising for a few years now. New theories about the role hydrogen can play and computer models could pick out promising compounds both are contributing to these new advances. For example, scientists found that lanthanum hydride could superconduct at between -13F and 8F, but at a pressure of 1.8 million atmospheres.

You can read more technical information on the Dias Group’s website. There’s a picture of the kind of diamond anvil used in these experiments on that site, too, and you can see it above.

Scientists still don’t totally understand why this compound is superconducting at the right temperature and pressure. Work is ongoing to identify the material’s structure and exact chemical formula.

It wasn’t long ago that even liquid nitrogen temperature superconductors were unheard of, but now you can make them yourself if you have some lab proficiency. You’ve been able to do that since at least 2018.

Photo credit: J. Adam Fenster, University of Rochester

24 thoughts on “Room Temperature Superconductor? Yes, But Not So Fast…

    1. “Their best result was a transition temperature of 287.7 kelvin at 267 gigapascals — 2.6 million times atmospheric pressure at sea level.”

      14,55 degrees celsius
      58,19 degrees fahrenheit

    1. Actually, you can simply use two coils… One on either side. Pass an AC current through one and observe the second. When the material in between goes through the superconducting shift, the magnetic fields around the secondary coil will very clearly change as the superconductor routes them around it instead of through it.

    2. To prove you reached superconductivity, you should check more of these phenomena:

      1. sudden drop of resistivity – measurable by Kelvin probes (4-point resistivity measurement). You actually can prepare diamond anvil cell with 4 gold wires. It is challenging for many reasons, for example wires can rip with slight movement of diamond during pressure increase. They also need to be insulated from metallic gasket
      2. Meissner effect – superconductor of type I (as one in the article) exerts all magnetic field from its volume (only small portion of surface gets penetrated-something like “skin effect” for magnetic fields). It can be measured by AC current and calculating magnetic susceptibility
      3. isotopic effect – superconductivity is inherently quantum effect. These are stronger for lighter particles. If you achieve to prepare same structure with deuterium, which has one neutron hence is heavier, you should observe lower transition temperature at given pressure compared to common hydrogen

  1. There’s always a catch. “Sure, you can have a room temperature superconductor…at 267 gigapascals! Ha ha ha!”

    Sometimes I think the universe enjoys playing with us like that.

    1. It’s not surprising. Imagine you’ve got a box filled with metal balls, and you’re shaking it a ton. None of the balls ever can stay in contact with others. Too much shaking. Stop shaking, and they’ll settle at the bottom and clump together. That’s how low temp superconductors can form.

      Now shrink the box until it’s barely bigger than the metal balls. Shake it all you want: the balls have nowhere to go. They’re still in contact with each other. That’s how high pressure superconductors can form.

      Another way to think about it is this: take an object, and put it under this pressure. What happens? It heats up, dramatically, and becomes molten. What would you need to do to get it *back* to room temperature? Cool it down. A ton.

      This is not a new idea: Ashcroft predicted hydrogen would be a high pressure superconductors back in the 60s. The new part is that they were finally able to reach these pressures.

  2. Waiting for an enzymatic reaction chain assembling organic ambient temperature superconductors filament.
    And supercaps. And solar -> electric direct conversion (with magnitude higher efficiency than photosynthesis)

    1. Gonna wait a long time for that last one, considering photosynthesis’s full-spectrum efficiency is 11%. Even if we ask for an order of magnitude *less energy lost* (instead of the obviously impossible 110%) that would be ~90% efficient, which is above the maximum theoretical limit for any technology.

      And if you ask for an order of magnitude higher efficiency than *plants*, we’re basically there for many plants.

  3. I bet if eventually a room temperature superconductor is found it will involve something like carbon(boiling point 4000K), tungsten (melting point 3695K) or tantalum(melting point 3290K). Something with a very stable structure near room temperature (300K).

    1. Not likely. High Tc superconductors basically work by having planar symmetry where free electrons from some high-Z element get trapped and end up pairing up. Then the superconduction basically happens along those planes. In some sense it’s kinda like the high-pressure situation: you’ve made it so that the electrons *can’t* get out of this tight band, and so these fragile but lower-energy coupled states start to get populated.

      There’s obviously a ton that’s not known about high-T superconductivity, but the basic fundamental idea’s always going to be the same: you need to restrict the states that electrons can be in, but allow them long-range interactions with “stuff” so pairing becomes common. Cooling down materials does this, as does high pressures.

      The strong physical structure of carbon, tungsten and tantalum are because they form body-centered cubic lattices, so there’s no “plane” where stuff like that can happen. Other allotropes of carbon, of course, can form planar structures (graphene) and those *have* been shown to superconduct in some cases. However, the fact that carbon *loves* to bond with effing everything in new and various ways makes it unlikely that it’ll be a *high* T superconductor (the graphene discovery was at near-absolute zero, as you’d expect). But, of course, carbon is Wacko Weird so who the heck knows on that.

      But really, in the end any high-Tc superconductor isn’t going to want to be “strong” fundamentally. Being strong means you can disperse sound waves throughout the whole object, which is a *terrible* idea for superconductivity.

      I’m not saying that carbon/tungsten/tantalum couldn’t be in a high-T superconductor, but they’d be there for their geometric/electronic properties rather than the fact that they can form super-strong lattices.

      1. It’s certainly British room-temperature beer temperature. But even liquid-nitrogen temperature is so much more practical than colder things; you can get it in bulk easily.
        Dry-Ice temperature would be even better. (-85C); you can get that stuff at the grocery store.

  4. superconductors.org has been claiming superconductivity well above 100 Celsius for several years, no applied pressure required. One problem is that the superconductive material can’t be made larger than microscopic sizes. Another problem is that humidity in the air breaks down the stuff fairly quickly.

  5. One is left to wonder though, if there is a line of sight to this being mass producible. Strain can be engineered into materials. Tempered glass has enormous internal strain. I’m no mech-e, but is it possible to engineer a structure that has tremendous internal pressures without requiring a diamond anvil? Perhaps not this level of pressure, but if we assume that the next few years of research will bring the required pressure down…

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