Photoemission study of the metal-insulator transition in NiS2-xSex

Mamiya, K and Mizokawa, T and Fujimori, A and Miyadai, T and Chandrasekharan, N and Krishnakumar, SR and Sarma, DD and Takahashi, H and Môri, N and Suga, S (1998) Photoemission study of the metal-insulator transition in NiS2-xSex. In: Physical Review B: Condensed Matter, 58 (15). pp. 9611-9614.

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Abstract

We have studied the electronic structure of NiS2-xSex, which undergoes a metal-insulator transition as functions of composition x and temperature, by means of photoemission and inverse-photoemission spectroscopy. Spectral changes across the transition near the Fermi level (E-F) (particularly within similar to 100 meV of E-F) have been interpreted as due to a "semimetallic" closure of the band gap in going from the insulating phase to the antiferromagnetic metallic phase. On the other hand, there is also composition- and temperature-dependent spectral weight transfer over a wider energy range of similar to 0.5-1 eV, indicating significant correlation effects. Photoemission intensity just below EF remains high in the insulating phases, indicating that the carrier number is large at high temperatures and that the activation-type transport is due to the activated mobility rather than the activated carrier number.

Item Type:	Journal Article
Additional Information:	Copyright of this article belongs to American Physical Society.
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	24 Dec 2009 11:30
Last Modified:	19 Sep 2010 05:26
URI:	http://eprints.iisc.ernet.in/id/eprint/19046

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