Layer stackings and physical properties of mixed-layer structure phases III: preparation of mixed-layer structure phases of ReXNb1-XSe2 and OsXNb1-XSe2 and some electrical and magnetic properties

摘要

The binary systems, ReSe2-NbSe2 and OsSe2-NbSe2 are studied. Mixed-layer structure phases are found in RexNb1-xSe2 of the composition range, 0.12 less than or equal to X<0.45, and in OsxNb1-xSe2 of the composition range, 0.10 less than or equal to X<0.33. The mixed-layer structures of both phases are constructed by random and mixed stacking of the 2H(b)-layers and 3R-layers. The WSe2-type 2H(b) phases are found in RexNb1-xSe2 of the composition range, 0.45 less than or equal to X less than or equal to 0.55, and in OsxNb1-xSe2 of the composition range, 0.33 less than or equal to X less than or equal to 0.35. A novel mixed-layer structure constructed with 1T-layers and 2H(b)-layers is found in OsxNb1-xSe2 of the composition range, 0.35 less than or equal to X<0.60. The magnetic susceptibilities of the samples of the mixed-layer phases show a weak Pauli-paramagnetism. Both the paramagnetic moments and the electrical conductivities of both phases decrease as the composition X increases. The behaviors of the paramagnetic moment and the electrical conductivity of those phases offer us a good example of the number of conduction electrons and their effect (C) 1998 Elsevier Science S.A. [References: 6]