Effect of Local Structure of NbSe2 on the Transport Properties of ([SnSe]1.16)1(NbSe2)n Ferecrystals
journal contributionposted on 24.03.2015, 00:00 by Matti B. Alemayehu, Matthias Falmbigl, Kim Ta, David C. Johnson
([SnSe]1.16)1(NbSe2)n ferecrystals were synthesized through the modulated elemental reactants technique by increasing the number of Nb|Se layers in the precursor from 1 to 4. The c-lattice parameter of the intergrowth was observed to change as a function of n by 0.635(2) nm. The c-lattice parameter of SnSe was observed to be 0.588(8) nm and independent of n. The electrical resistivity does not decrease as n increases as expected from simple models, but instead the trend in the resistivity is (1,3) > (1,4) ≥ (1,1) > (1,2). The carrier concentration increases with n as expected, so the unusual trend in resistivity is a result of the carrier mobility decreasing with increasing n. In-plane X-ray diffraction line widths and STEM images of the (1,4) compound show that it has small in-plane grain sizes and a large diversity of stacking sequences respectively, providing a potential explanation for the reduced carrier mobility.