Structure determination of a new misfit layer compound (PbS)1.18(TiS2)2

Abstract

(PbS)1.18(TiS2)2 is a misfit layer compound in which two types of slabs, PbS and 2(TiS2), alternate along the c direction. The |TiS2| blocks (about 11.39 Å thick) are interleaved by |PbS| layers, thus leading to a value for c of 17.46 Å. The misfit between the two slab types occurs along the a direction; the parameter values being a(PbS)=5.761 A ̊ and a(TiS2)=3.390 A ̊ respectively. This yields a ratio of approximately 1.699, which is irrational but close to 5/3. The common in-plane b parameter is equal to 5.873 Å. The PbS unit consists of a {001} slice (half an edge thick) of an NaCl-type f.c.c. cell. © 1992.