A new ordered state characterized by sharp electron diffraction spots showing an arrangement with a twelvefold symmetry axis inconsistent with the existence of a Bravais lattice has been found in small particles of Ni-Cr. Electron microscopic high-resolution structure images of these particles reveal that this ordering state has no translational symmetry but has far-reaching orientational order.

• Received 13 December 1984

DOI:https://doi.org/10.1103/PhysRevLett.55.511