2024/01/22 by van Smaalen, Sander
#530 #Aperiodic crystals #Crystal structure #Modulated crystals #Quasicrystals
paper · doi:10.15495/epub_ubt_00007434
Aperiodic crystals are ordered matter without three-dimensional (3D) translational symmetry. They encompass quasicrystals, incommensurate composite crystals and incommensurately modulated structures. Their crystal structures are described by the so-called superspace theory, in which hidden periodicity is uncovered as translational symmetry in a space of dimensions higher than three. Here, I give an introduction to the structural features of aperiodic crystals and to the superspace theory for describing those structures. Applications, in particular t-plots, are demonstrated for the charge-density wave (CDW) materials Er₂Ir₃Si₅ and EuAl₄.