MISFIT LAYER COMPOUNDS (SbS)_1.15(TiS₂)_n WITH n=1,2. Y. Ren^a, A. Meetsma^a, S. van Smaalen^b, V. Petricek^c, C.H. Ruecher^d, C. Haas^a, and G.A. Wiegers^a. ^aChemical Physics, University of Groningen, 9747 AG Groningen, The Netherlands; ^bLab for Crystallography, University of Bayreuth, 95440 Bayreuth, Germany; ^cInstitute of Physics, Czech Academy of Sciences, 16200 Praha 6, Czech Republic; ^dInstitute for Mineralogy, University of Hannover, 30167 Hannover, Germany.

The incommensurate crystal structures of the misfit layer compounds have been determined on the basis of a (3+2)-D superspace-group using single crystal X-ray diffraction. The structures are built up by alternating stackings of double layers SbS and single or paired sandwiches TiS₂. The SbS double layers consist of an intrinsical interface modulation. The distinguishing feature is the incommensurate ordering of Sb/S atoms on the distorted rock-salt structure of SbS, which results in Sb-Sb and S-S clusters. The electronic structure has been studied using photoelectron spectroscopies. 22% of the total Sb atoms are in Sb-Sb contacts. All spectrum peaks are broadened by the mutual interaction of the two subsystems. The top valence band consists mainly of S 3p states and the conduction band of Ti 3d states. The study of their electrical transport and optical properties shows a 2D Fermi-liquid behaviour.