On the existence of periodic interfaces in the layered compound TlBiS2

Abstract

Single TlBiS2 crystals are studied by transmission electron microscopy. It is found that the compound has a very long period superstructure -in addition to an already known one due to ordering of Tl and Bi atoms on separate (111)(R) planes- which rises by periodic ordering of (114)(R) interfaces in the basic superstructure matrix. Models for this superstructure, which is probably related to composition modulation are proposed.