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Science

The Incredible Shrinking Compound 36

Posted by Hemos from the ker-ploof-now-it's-gone dept.
MrByte420 writes "This Rueters article talks about everyone's household product of the future, zirconium tungstate. This unusuall metal actually shrinks when heated contrary to most other compounds. This property holds within a huge temperature range shrinks uniformly making it a very pratical substance to work with. The huge potential is already being explored in areas such as better Fiber Optics, Chips that don't burn out, better dental fillings, and racing cars."
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The Incredible Shrinking Compound More

The Incredible Shrinking Compound

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  • ice shrinks (Score:2, Funny)

    by agnosonga ( 601770 )
    ya, ok its not a metal but ice shrinks when its heated
    • In this case the ice doesn't shrink, it melts. Conversion from one form to another. The metal doesn't do that, it maintains the same amount of material (assuming I read it correctly)

      • Re:ice shrinks (Score:1, Informative)

        by Anonymous Coward
        No, actually, ice does shrink before it melts, in a very similar manner to the compound in the article. And between 0 and 4 degrees C, the liquid water continues to shrink as the temperature rises. (at constant pressure...)
      • waters minimum density is at 4C, as it approaches freezing from there, it expands. It's not a solid, but that's still a negative coefficient of thermal expansion, and neither one changes the amount of material.
        If it did, now THAT would be a really big deal - the creation and destruction of matter by temperature change.
      • Actually, ice does shrink. It's only in a limited range (right around the freezing point) that ice expands. Then, as the temp. is lowered, it shrinks.

    • Water also shrinks a little as it is heated, but only from freezing point to just above freezing point.

      Although several materials exhibit this unusual property, zirconium tungstate is the only one known so far to show the behavior at a constant rate and at room temperature. Unlike the other compounds, it also shrinks equally in all directions.

    • All of this will make your Fiance feel much better about the Zirconium - which you told her was a Diamond!

      "Gosh honey, they even call 'em 'ice'..."

  • Slashback (Score:3, Funny)

    by PhysicsGenius ( 565228 ) <`moc.oohay' `ta' `rekees_scisyhp'> on Sunday September 29, 2002 @09:38PM (#4356258)
    Be amazed all over again [slashdot.org]!

    (I claim an extra 2 "Informatives" by reason that it was the same editor that posted this both times)

    • Time for a meta article on "The Incredible Shrinking Attention Span". Oh wait... the editors are too afraid to post meta articles. All of the criticisms of this site would be on-topic, making it harder to use mod-bombing or IMP or whatever. *sigh* Wake up, editors. This stuff is getting old.

  • "... up to a red-hot +777 degrees."

    at a first glance, this is what the tired UNIX geek sees

    "... up to a red-hot +rwxrwxrwx degrees."

    • "... up to a red-hot +777 degrees."

      at a first glance, this is what the tired UNIX geek sees

      "... up to a red-hot +rwxrwxrwx degrees."

      And at first glance this is what a tired airplane geek sees:

      "... up to a red-hot +300-550_passenger_airplane degrees."

      ...

      I work for Boeing, I worked on the newest 777 last year. Any time that I see a pattern of numbers 7_7, I think of a Boeing airplane. Heh, I saw a story today which had 747 total comments, and I did a double-take.

    • Personally, I think of Kabbalah [research-systems.com] and numerology [tripod.com], but I guess I'm just weird for reading meaning into random numbers, aren't I?
  • Ok, so if this metal shrinks when it gets hot, does that mean that if your processor runs hotter, then it might run more efficiently? Or would that efficiency be lost because of the added heat to disturb the flow of the electrons? Perhaps they could create the chips in a cooler environment then expose it to normal temperatures to bring the micron sizes down further? Either way, shrinking metal sounds pretty cool to me.
  • The article is short on properties other then thermal contraction. If it generally behaves like a metal it may be drawn into a wire. Combined with resistive heating it could be used as a crude muscle. Unfortunately that Oxygen in the lattice leads me to believe it's very brittle in the same way that most oxides are, Iron Oxide comes to mind.

    Still it may well find itself in nanostructures as a crude muscle where ductility is of less importance.

    • Re:Article short on properties (Score:4, Informative)

      by Raiford ( 599622 ) on Sunday September 29, 2002 @10:43PM (#4356637) Journal
      Short on properties and confusing in application. Since the stuff is called Ziconium Tunstate then by definition it is an oxide and thereform must be processed by ceramic processing techniques. For example pressing, extruding, slip casting and finally sintering. I doubt that wires are something that is viable for this stuff. Microelectronic packaging is very likely since ceramics play a big role there. However much would depend on the dielectric properties of the material. Since it is a tungstate compound it most likely has a crystalline structure which has a fairly high defect density giving rise to some electronic conductivity.

      I'm not quite clear on the reference to fiber optics. Where would the stuff go. It certainly would not make a good optical propagation medium since it is not isotropic and would have to be processed as a polycrystalline materail. There was a cryptic reference to gratings with no details so I guess there is the application but it escaped me.

  • The one thing that struck me about the article is that the author must have previously believed that all solids expand when hot. He refers to it in some places as a law of physics or a "supposedly inviolable rule". That is silly. Everyone knows that ice expands when it cools and therefore shrinks when it heats up. If one fairly common compound can do it, there are probably several more that can as well. This one just happens to do it quite well.
    • just another example of not reading the article in its entirity! The author clearly states that water has this property but only within a very small temperature range.
  • The huge problem in canada, are the side walks tha break, or roads that constantly crack. That is due to the expanding in summer and contracting in winter... Would it be possible to mix cement with the compond so that it counters the effect, or at least dimishes the damages ?

    • Re:How bout cement? (Score:3, Informative)

      by Vinum ( 603982 )
      A lot of that is due to two reasons... long periods in the summer without rain cause the ground to shift and crack and it screws up roads and building foundations. That is why it is good to water your lawn frequently in the summer, to save your foundation in low rain areas.

      Also... when water gets in the cracks between your sidewalk and freezes the ice expands and pushes the cracks further apart. This has devestating effects on roads and sidewalks. The only way to stop this on roads and sidewalks would be to remove the very thing that makes them useful... the rough surface on top ;)

  • Very Old News (Score:4, Informative)

    by QuantumWeasel ( 606327 ) on Sunday September 29, 2002 @10:30PM (#4356558)
    See for example the work at Bell Labs [bell-labs.com] reporting in 1998 which was also reported in the journal Nature [nature.com] (subscription required) as early as 1997. The mechanism by which this broad negative-TCE occurs is nonetheless spectacular -- the zirconia atoms basically get pulled in and fold over against each other as the oxygen atoms vibrate more intensely with heating. This recent announcement (and several more in the last few years) are Soundbite Science.
  • Would it be possible to mix this with other metals so that the resulting substance wouldn't change size at all under any temperature changes?
    • It could be mixed heterogenously to form a mechanical mixture with another metal. This would lower the effective thermal expansion of the mixture; however, these type of systems tend to degrade the mechanical properties. If the material were alloyed the crystal structure of the tunstate phase would be altered and the anomolous volumetric expansion would probably be lost.

  • Ok, of course, the article was quite short on details. But does anyone out there know what the mechanism is in this metal that makes it contract when it heats? This seems to me counterintuitive, and I can't imagine how it works.

    I also don't even know where to go for some technical literature, since I'm not a materials scientist.

  • Worst. Spelling. And. Grammar. Ever. (Score:5, Funny)

    by fruity1983 ( 561851 ) on Monday September 30, 2002 @02:11AM (#4357437)
    What is wrong with this guy?

    "Rueters"??? ITS REUTERS!

    "unusuall" . . . do I, need... ARGH!

    Look at the grammar! This guy reads slashdot, and he hasn't passed grade 5 english?

    "This property holds within a huge temperature range shrinks uniformly making it a very pratical substance to work with."

    What is a 'temperature range shrinks'??? I cant even make sense out of this nonsenseness in order to make a sensical joke about the nonesenseness of this sentence!
  • Come on. Any child of the 70s knows that there are things [shrinkydinks.com] that shrink when heated.

  • Here's a how-I-understand-it description:

    The problem with wires is that they expand; the more heat/current passing through, the more expansion. If you're trying to propagate a wave through something that's slightly cone-shaped (rather than tubular), the wave will lose some of its integrity (it'll get larger rather than keeping its original shape). Also, if the wire gets smaller as you heat it (like using ZrW2O8 for the entire thing), the wave will be distorted (it'll get smaller and smaller).

    Fiberoptics use a combination of materials: one that is essentially a traditional wire, and one that shrinks when heated. This produces an expansion in the normal stuff, and shrinks the other, creating a net expansion of zero! This way, the cable stays essentially the same size its entire length, and can propagate your signal with few distortions.

    Substances that shrink when heated aren't new, and ZrW2O8 isn't new either. Here's a 1998 PDF from NIST [nist.gov] on the stuff.

    The first few pages of this nice PDF have a history [hlinstruments.com] of fiberoptics (the rest is an ad for the company).

  • I have the luxury of a pet dental resident who is required to use new technology in his work, and as a result, I recently got one of these shrinky-dink filings. And let me tell you - though the inital pain is unbearable, after a day the pain is gone and the nerve is covered much more completely than the conventional filling materials. Having the worst teeth in the world (ok, maybe it was the 20 yrs w/o dental insurance..), I have too much exp w/ fillings going bad after a couple years, and this technology is a boon to anyone who's had a filling come out and a root canal ensue. The proof is, as they say, in the pudding, so I'm going off to lunch on it.

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