抄録
A layer of MS was intercalated into the van der Waals gap of TiS2 layers to form a “natural superlattice” (MS)1+x(TiS2)2 (M = Pb, Sn, Bi) and the lattice thermal conductivity was much decreased because of softening of transverse sound velocities. Moreover, the stacking manners of the MS and TiS2 layers can further tune the lattice thermal conductivity. A translation displacement of the SnS layer relative to its neighboring TiS2 layer in (SnS)1.2(TiS2)2 and and the stacking disorder of the BiS and TiS2 layers in (BiS)1.2(TiS2)2 can systematically reduce the thermal conductivity to an extremely low level. Raman spectrum was then used to analyze the vibration modes of these materials to understand the unusual thermal conductivity mechanism.
