Characterization and electrical transport properties of the misfit layer compounds (BiSe) 1.10NbSe 2 and (BiSe) 1.09TaSe 2

Abstract

Compounds (BiSe) 1.10NbSe 2 and (BiSe) 1.09TaSe 2 were prepared by high-temperature reaction of the elements. Crystals were grown by vapor transport. The misfit layer compounds are built of alternate sandwiches NbSe 2 (TaSe 2) with Nb (Ta) in trigonal prisms of Se and interface modulated double layers of BiSe; 1 3 of the Bi atoms are at distances of 3.19 Å across the interface. Electrical transport properties (resistivity, Hall effect and Seebeck effect) are in agreement with conduction by light holes and heavy electrons in the 4d z 2 band of NbSe 2 (5d z 2 band of TaSe 2). There is no significant electron donation from BiSe to NbSe 2 (TaSe 2); three 6 p electrons per Bi being used for Bi-Se and Bi-Bi bonds.