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Science

High-Density Magnets Created 30

Judebert writes: "University of California, Riverside scientists have created diradical magnets: magnetic particles that have two unbonded electrons instead of just one. The problem with diradical substances is that they have always been extremely chemically active, so they never stayed around longer than a few microseconds at room temperature. The new substance is stable at room temperature, even when it's in solution. And it's not even metallic. This paves the way for newer, higher-density magnetic and magneto-optical media and devices. You can help distribute the load if you visit the text mirror instead."
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High-Density Magnets Created

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  • This is just what I needed to fix that old High Density disk drive in my XT

    W00t!
  • by PD ( 9577 )
    The article said that a car uses 300 parts that use magnetism. I can't think of anything more than the cassette tape player, and that's optional. Maybe in the dashboard there's some?

    Wait, the solenoids that are on the starter. But what others?
    • Re:car parts (Score:3, Informative)

      by Anonymous Coward
      Let's see. All the analog displays in your dash have magnets. Tach, speedo, ..anything with a needle. Alternator, starter, various motors, speakers. Also magnets that measure the rpm of various mechanical bits via magnets and sensor that rely on the Hall effect.

      And those are all permanent magnets. If you gifure in electromagnets, there's probably one in any circuit of any size in the form of relays, chokes, coils, solenoids, sensors. I think 300 is a reasonable number.
    • Re:car parts (Score:3, Informative)

      by teridon ( 139550 )
      In some cars, the oil/tranmission drain plug is magnetic. Some transmissions have a magnet in the fluid pan to catch metal filings. Most cars have radios, and thus speakers with magnets.
    • Re:car parts (Score:2, Informative)

      by 3waygeek ( 58990 )
      Here's a few -- alternator, solenoids on power door locks, motors on power windows, fan motors.
    • think:

      - alternator (create electricity through magnetic induction of currents)
      - relays
      - stereo speakers
      - rotor in the distributor cap
      - engine fan (for electric, non-belt driven types)
      - solenoids in any electric trunk/hood releases and power locks
      - electric motors in power windows/mirrors

      that's just off the top of my head... there really are a lot of magnetic parts in a car. Most are electric magnets, true, but magnetic nonetheless.

  • what exactly? Is there something fundamentally different about these diradicals that make them better for some uses? All that the article says is that it's more magnetically active.

    My understanding of electronics is pretty basic, but is the amount of charge really important for electronics? You can make stronger magnets to generate electricity and other applications that use strong magnets, but my understanding was that most electronics were independant of the strength of the magnet.

    Why am I wrong about this? (I assume that there is some important advantage here?)
    • stronger magnets = higher storage density on magnetic devices.

      also, stuff won't fall off the fridge when you slam it shut.
    • by mbessey ( 304651 ) on Thursday March 14, 2002 @12:54AM (#3161121) Homepage Journal
      For any application that uses magnets, higher magnetic strength is always an asset. Whether it allows you to reduce the weight of an assembly, or increase the amount of force for a given volume/weight, it's a good thing. Stronger magnets also allow you to store more data in a smaller area in a magnetic storage device, as someone else already mentioned.

      Also, these "diradical" magnets are a fundamentally different kind of material than other magnets, which means that they may have other properties that allow the use of magnets where they couldn't be used before.

      -Mark
    • Frinstance, those small lightweight headphones that you use with your walkman were a miraculous innovation about 20 years ago, and what made them possible was advances in magnet technology. Before that, headphones of that quality weighed a couple pounds.

      Right now, electric motors for e.g. hybrid vehicles could really use better magnets. Pull out your McMaster-Carr and see what a 200 horse high starting torque DC motor weighs, and how big it is. It's impressive.

  • Loudness (Score:3, Funny)

    by Deanasc ( 201050 ) on Wednesday March 13, 2002 @08:21PM (#3160225) Homepage Journal
    So can I get even louder headphones for my Mp3 player? Imagine how much quicker I can loose my hearing listening to my pirated CD's.
  • by Veramocor ( 262800 ) on Wednesday March 13, 2002 @09:07PM (#3160451)
    RIAA/MPAA just announced the second free electron will be used for DRM.

    Veramocor
  • by yancey ( 136972 ) on Wednesday March 13, 2002 @09:22PM (#3160508)

    As we move toward using more fuel cells and electric motors, this may be one of the more important scientific discoveries of the decade.
    • Why? Please explain Yancey!
      • by TwP ( 149780 ) on Thursday March 14, 2002 @01:37PM (#3163152) Homepage
        The force (or power) an electric motor can generate is directly proportional to the current going through the motor and the strength of the magnetic field. If the magnetic field is stronger, you can have a motor of the same size but with more power. Or you could have a motor of the same size and power, but it would consume less current. This would give you a longer battery life.

        For cars, you could now have more powerful electric motors that consume the same amount of power as current electric motors. Or you could have electric motors with the same power output of todays models but with a lower power consumption.

        Stronger magnets make for more effecient electric motors. You can use that efficiency for greater power or greater battery life.

        • I was under the impression that electric motors
          were already quite efficient.

          I looked at some numbers, and even without these
          new magnets, electric motors are often 90%
          efficient or better.

          I tend to think that the primary gain of a better
          magnet is, if anything, the ability to make
          the motors smaller.

          I think the main waste of power in an electric
          motor has nothing to do with the strength
          of the magnet, but rather resistive losses
          in the coils.
          • It is true that electric motors are very efficient, but this ultra-strong magnet technology does not profess to increase the efficiency, but the power output. If you have a motor with 90% efficiency, you need to find a way to raise the gross output, not the efficiency. In internal combustion engines, which are anywhere between 10% and 25% efficient, raised efficiency is a huge bonus, but not in electric motors.

            Stronger magnets will yield stronger electric motors, which may be able to finally bring them into the popular consumer automobile market. The powerful electric motor is the key to electric cars, because battery technology appears to have run its course (seen in a recent /. article).
  • "The problem with diradical substances is that they have always been extremely chemically active, so they never stayed around longer than a few microseconds at room temperature."

    Erm, if I remember my basic LCAO/MO theory from first year chemistry atmospheric oxygen, yes O2, is a diradical as is Fremy's salt, which I made in second-year labs and they hang around for longer than a couple of microseconds.

    Talk sense boyo.

    Elgon
    • Re:Ummm no (Score:2, Informative)

      by Veramocor ( 262800 )
      Oxygen has 6 valence electrons. lets draw one of those nifty electron valence shell models. Each dot is an electron.

      .
      :O.
      ..

      Oxygen "wants" a complete electron shell so it forms a double bond with another oxygen, each sharing its 2 unpaired electrons.

      O=O

      no radicals there.

      Veramocor
      • looks like you are right. using simple models you would get unpaired electrons but not with MO theory.

        ChemE to much engineering not enough chem
      • It was a balanced molecule where two Boron atoms seemed to have their vallence atoms "shielded" from contact with other molecules. Considering that the flat layout is actually a representation of a 3D structure, I could see how the "leafs" could curl up so that nothing else could get to the Boron.

    • Re:Ummm... (Score:3, Informative)

      by ndevice ( 304743 )
      i'm not a chemist, but:

      reading from the article, they seem to say that diradicals like O2 are already bonded and not very magnetic. I remember the LOx and magnet demonstration in chemistry class, and it wasn't that impressive. What these guys have done is find a molecule/compound that doesn't bond (and doesn't lose the magnetic effects of being a diradical)

      anyway, quoting from the article:


      Several research groups worldwide have shown that materials based on "diradicals" will be even more magnetically active. In a diradical, two atoms, which are close to each other, have electrons ready to form a bond. And indeed, the difficulty is that usually the bond is formed, resulting in no magnetism.


  • by dario_moreno ( 263767 ) on Thursday March 14, 2002 @05:36AM (#3161629) Journal
    The leader of the group is french, and still
    manages his lab in Toulouse. The project
    is half french, half american, and students
    travel continuously in between the two labs.

  • Now we all just have to wait until someone invents the one-direction magnet. It has to exist (according to Einstein), but no one has been able to even conceive of a way to do it yet. Perhaps this stable singlet diradical substance is just a step or two below uni-directional magnetism.

    Continue magnet research!
  • IANA Material Science Physicist, but IIRC usual magnets are monoatomic arrays of atoms/ions with a free electron, which due to inter-spin hamiltonian do a phase-transition to unidirectional spin (so called Ising model).

    except for the fact that here are pairs of different atoms with radical electrons, what is the difference from Ising model ?

    why does this give higher free-electron (hence magnetic field) density than normal monoatomic magnets ?

    what am I missing ?

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