On the nature of the top of the valence band in layered Mo and W dichalcogenides

Abstract

AbstractThe magnetic susceptibilities of single crystals of MoS2, MoSe2, α‐MoTe2, and WSe2 are measured between 2 and 300 K. Above 60 K the susceptibilities are temperature independent and strongly anisotropic. The observed anisotropy is attributed to Van Vleck temperature‐independent paramagnetism of the d electrons. The electrical resistivity and the Hall effect of As‐doped p‐type single crystals of MoS2, MoSe2, α‐MoTe2, WS2, and WSe2 are measured between 2 and 300 K. Electron paramagnetic reasonance of p‐type crystals of MoS2, MoSe2, α‐MoTe2, WS2, and WSe2 shows strongly anisotropic g‐values. An explanation of these g‐values is not possible in terms of only metal d‐orbitals or only chalcogen p‐orbitals, but requires a strong mixing of d‐ and porbitals in the top of the valence band.