Synthesis and Thermal Properties of Solid-State Structural Isomers: Ordered Intergrowths of SnSe and MoSe2
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- 作者：Noel S. Gunning ; Joseph Feser ; Matt Beekman ; David G. Cahill ; David C. Johnson
- 刊名：Journal of the American Chemical Society
- 出版年：2015
- 出版时间：July 15, 2015
- 年：2015
- 卷：137
- 期：27
- 页码：8803-8809
- 全文大小：431K
- ISSN：1520-5126
文摘
A family of structural isomers [(SnSe)1.05]m(MoSe2)n were prepared using the modulated elemental reactant method by varying the layer sequence and layer thicknesses in the precursor. By varying the sequence of Sn鈥揝e and Mo鈥揝e layer pairs deposited and annealing the precursors to self-assemble the targeted compound, all six possible isomers [(SnSe)1.05]4(MoSe2)4, [(SnSe)1.05]3(MoSe2)3[(SnSe)1.05]1(MoSe2)1, [(SnSe)1.05]3(MoSe2)2[(SnSe)1.05]1(MoSe2)2, [(SnSe)1.05]2(MoSe2)3[(SnSe)1.05]2(MoSe2)1, [(SnSe)1.05]2(MoSe2)1[(SnSe)1.05]1(MoSe2)2[(SnSe)1.05]1(MoSe2)1, and [(SnSe)1.05]2(MoSe2)2[(SnSe)1.05]1(MoSe2)1[(SnSe)1.05]1(MoSe2)1 were prepared. The structures were characterized by X-ray diffraction and electron microscopy which showed that all of the compounds have very similar c-axis lattice parameters and in-plane constituent lattice parameters yet distinct isomeric structures. These studies confirm that the structure, order, and thickness of the constituent layers match that of the precursors. The cross-plane thermal conductivity is found to be very low (鈭?.08 Wm鈥? K鈥?) and independent of the number of SnSe鈥揗oSe2 interfaces within uncertainty. The poor thermal transport in these layered isomers is attributed to a large cross-plane thermal resistance created by SnSe鈥揗oSe2 and MoSe2鈥揗oSe2 turbostratically disordered van der Waals interfaces, the density of which has less variation among the different compounds than the SnSe鈥揗oSe2 interface density alone.