Angle-resolved photoemission study of Ni-intercalated 1T-TiS2

Angle-resolved photoemission spectra have been measured to study the electronic structures of Ni intercalated layered compound Ni1/3TiS2. The results have shown that some new bands appear in Ni1/3TiS2 and the dispersions of most other bands are strongly modified compared with TiS2. It is clarified that the new band near the Fermi level (EF) is the split-off state or the bonding state between the final states originating from the /d(1)(t(2g))] and /d(2)(t(2g),e(g))L] initial states, where L stands for the S 3p hole state. Another new band observed at similar to 1 eV below E-F is hardly dispersive and attributed to the Ni3d(z2)-Ti3d(z2) bonding state. The Ni 3d' ' e(g) ' '-S 3p bonding states are observed in the larger binding energy region. Knowledge of hybridizations among the 3d states of the intercalant, Ti 3d states, and S 3p states are essential to interpret the physical properties of Ni1/3TiS2.