Para- to ferromagnetic phase transition of CoS2 studied by high-resolutionphotoemission spectroscopy - art. no. 094415

We have performed temperature-dependent ultrahigh-resolution (DeltaE simila r to7 meV) photoemission spectroscopy on CoS2 across the para- to ferromagn etic transition and found a remarkable temperature-induced spectral change near E-F. Comparison with the band-structure calculation shows that a sharp peak at E-F in the photoemission spectrum below Curie temperature (120 K) is ascribed to the e(g)down arrow subband due to the exchange splitting, in dicating that the e(g)down arrow band is partially filled in the ferromagne tic phase. The present photoemission results indicate that the electronic s tructure and the magnetism of CoS2 are qualitatively well described by the band-structure calculation although the correlation effect substantially mo difies the electronic structure.