Non-uniform doping across the Fermi surface of NbS₂ intercalates

Magnetic ordering of the first row transition metal intercalates of NbS₂ due to coupling between the conduction electrons and the intercalated ions has been explained in terms of Fermi surface nesting. We use angle-resolved photoelectron spectroscopy to investigate the Fermi surface topology and the valence band structure of the quasi-two-dimensional layer compounds Mn_1/3NbS₂ and Ni_1/3NbS₂. Charge transfer from the intercalant species to the host layer leads to non-uniform, pocket selective doping of the Fermi surface. The implication of our results on the nesting properties are discussed.