The annotation that Israeli scientist Dan Shechtman scribbled into his lab notebook on 8 April 1982 was as astounding as it was brief: “10fold???” At the time it was held that only periodic atomic lattices possessed the requisite order to diffract a beam of electrons into a pattern of points, or Bragg peaks. And geometry plainly demands that such lattices have two-, three-, four-, or sixfold rotational symmetry.
Shechtman’s aluminum–manganese alloy, however, produced the crystallographically forbidden, tenfold-symmetric diffraction pattern1 shown in figure 1. The material was soon recognized as a quasicrystal, the first in a fundamentally new class of ordered solids. (See PHYSICS TODAY, February 1985, page 17.) For its discovery, Shechtman was awarded the 2011 Nobel Prize in Chemistry.
At the time of the milestone discovery, Shechtman was on sabbatical from his professorship at the Technion–Israel Institute of Technology in Haifa and working at the National...
