Electronic structure and the metal-insulator transition in NiS2-xSex

Matsuura A. Y., Shen Z. X., Dessau D. S., Park C. H., Thio T., Bennett J. W., Jepsen O.

Stanford Univ Dept Appl Phys Stanford Ca 94305
Stanford Univ Stanford Synchrotron Radiat Lab Stanford Ca 94305
Nec Res Inst Princeton Nj 08540
Max Planck Inst Festkorperforsch D-70569 Stuttgart Germany

We studied the metal-insulator transition in the NiS2-xSex system in x=0 and x=0.5 single crystals using angle-resolved photoemission. A narrow band, characteristic of many-body effects, develops near E(F) for x=0.5. This feature shifts away from E(F) at the transition temperature, a discontinuous change at the metal-insulator transition in a Mott-Hubbard system. We discuss our data in the context of recent theoretical calculations of the Hubbard model. The spectra support the general finding that a narrow peak of many-body nature develops at E(F) during the insulator-to-metal transition.

Physical Review B, 53 R7584, 1996.

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