The Incredible Shrinking Compound

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."

Comments

Very Old News

[QuantumWeasel]

See for example the work at Bell Labs reporting in 1998 which was also reported in the journal Nature (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.

Re:How bout cement?

[Vinum]

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 ;)

Re:Article short on properties

[Raiford]

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.

Re:Mixing with other metals

[Raiford]

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.

Re:ice shrinks

[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...)