CHARACTERIZATION, ELECTRICAL-TRANSPORT AND MAGNETIC-PROPERTIES OF THERARE-EARTH MISFIT LAYER COMPOUNDS (TBS)(1.21)NBS2, (TBS)(1.20)TAS2, (DYS)(1.22)NBS2 AND (DYS)(1.21)TAS2

X-ray powder and single-crystal X-ray diffraction of the title compoun ds showed that they are planar intergrowth compounds, built of alterna ting sandwiches TS2 (T=Nb, Ta) and double layers LnS (Ln=Tb, Dy), pres ent in three orientational variants related by rotations of 120 degree s around the c axis perpendicular to the layers. The TS2 and LnS subsy stems are incommensurate along one of the in-plane axes. The LnS subsy stem in each domain is face-centered orthorhombic. The stacking of the TS2 sandwiches shows disorder and the stacking type C or F could not be elucidated. The structures of the TbS subsystem and the common proj ection (TbS)(1.21)TaS2 were determined using single-crystal X-ray diff raction. The Tb-S distances are in agreement with trivalent Tb. The re sistivity, Hall effect and thermopower measured for crystals and compa cts point to conduction in an almost filled d(Z)2 band of the NbS2 and TaS2 sandwiches corresponding to an electron donation of about 0.85 e lectron per T atom from LnS to TS2. Magnetic susceptibilities, measure d in the range 4-300 K, are Curie-Weiss with effective magnetic moment s close to those for free Ln(3+) ions. The Curie temperatures are clos e to zero.