Core-level lineshapes in photoemission from transition-metal intercalates of TaS2

Abstract

The photoemission lineshapes of the Ta 4f levels in 2H-TaS2 and its intercalates Mn14/TaS2 and Co13/TaS2 have been studied using synchrotron radiation. The peaks show marked asymmetries because of the many-electron screening response to the core-hole potential. The different lineshapes are discussed in terms of the rigid band model of the electronic structure of the intercalates, and of the effects of charge transfer into the narrow conduction band on the many-electron response. Calculations of the lineshapes using a simple model for the conduction band density of states allow the experimental lineshapes to be understood in terms of intrinsic losses through multiple excitations within the narrow conduction band, together with some extrinsic plasma losses.