Photoelectron spectra of 2H-TaS2and SnxTaS2

Abstract

Photoelectron spectra of Sn_1/3TaS₂ and SnTaS₂ are reported and compared with spectra of 2H-TaS₂ and SnS. It is possible to trace the charge transfer from Sn to Ta from the observed increase of the occupation of the lowest Ta 5d band and from the observed decrease of the positive charge on Ta. The charge transfer is the same in Sn_1/3TaS₂ as in SnTaS₂. The data indicate the presence of two types of Sn atoms in SnTaS2. The Ta 4f peaks show an asymmetric broadening; and an anomalous intensity ratio of the 4f₇ and 4f_5/2 peaks. These effects are ascribed to shake-up effects involving excitations of 5d electrons. The average relaxation energy of a Ta 4f hole is found to be 1.1 eV.