Crystal matchmaker
Having evolved from mathematical playthings to curiosities of physics, the structures known as quasicrystals could become great tools for the electronics industry.
Like crystals, quasicrystals are built from units of atoms arranged in an orderly fashion. But, unlike crystals, quasicrystals have building blocks that interlock in a pattern that doesn’t repeat at regular intervals (SN: 10/12/96, p. 232).
Wolfgang Theis of the Free University of Berlin and his collaborators have now shown how to use layers of quasicrystals as connecting interfaces between different types of crystals that wouldn’t otherwise match up well at the atomic scale.
The researchers grew an aluminum arsenide crystal on the surface of an aluminum-arsenic-cobalt quasicrystal. The two structures meshed well because the distances between each surface atom of the crystal and its nearest neighbor on the quasicrystal’s surface were roughly, although not exactly, the same, the team reports in the July 20 Physical Review Letters.
Theis adds that it should be possible to fabricate a quasicrystalline structure that’s a good match for any two crystal types. It could then mesh with different crystals on its two surfaces, holding them together.
The technique might enable electronics manufacturers to use a wider range of semiconductors in chips, says Renee Diehl of Pennsylvania State University in University Park. The quasicrystal scheme is “a clever idea that has been around for awhile,” Diehl says, “but this is the first demonstration that it can be achieved, as far as I know.”
