On Aug 23, 2013, at 2:24 PM, Warren D Smith <warren.wds@gmail.com> wrote:
Phys Rev Lett. 2013 Jul 5;111(1):015502. Highly ordered noncrystalline metallic phase. Long GG, Chapman KW, Chupas PJ, Bendersky LA, Levine LE, Mompiou F, Stalick JK, Cahn JW. Abstract We report the characterization of a unique metallic glass that, during rapid cooling of an Al-Fe-Si melt, forms by nucleation, followed by growth normal to a moving interface between the solid and melt with partitioning of the chemical elements. We determine experimentally that this is not a polycrystalline composite with nanometer-sized grains, and conclude that this may be a new kind of structure: an atomically ordered, isotropic, noncrystalline solid, possessing no long-range translational symmetry.
I just looked this up and it seems that structurally this stuff is no more remarkable than a typical network glass, like Si O_2. However, there is one angle that makes the find potentially very interesting. Physicist and chemists have been trying for decades to describe the structure of network glasses (such as Si O_2), not with much success (interpret "describe" roughly as "specify a construction algorithm"). But with the AlFeSi glass there may be a window of opportunity not available before. This compound also has crystal and quasicrystal forms at very similar composition (Si O_2 only has a crystalline relative). Also, it turns out that the crystalline and quasicrystalline forms can be described as different arrangements of the same tiles. Perhaps the glass structure is a further level of scrambling of these building blocks. -Veit