Pal, Prabir and Kumar, Pramod and V., swin and Dogra, Anjana and Joshi, Amish G. (2014) Chemical potential shift and gap-state formation in SrTiO3-delta revealed by photoemission spectroscopy. Journal of Applied Physics, 116 (5). ISSN 0021-8979

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Abstract

In this study, we report on investigations of the electronic structure of SrTiO3 annealed at temperature ranging between 550 and 840 degrees C in an ultrahigh vacuum. Annealing induced oxygen vacancies (O-vac) impart considerable changes in the electronic structure of SrTiO3. Using core-level photoemission spectroscopy, we have studied the chemical potential shift (Delta mu) as a function of annealing temperature. The result shows that the chemical potential monotonously increases with electron doping in SrTiO3-delta. The monotonous increase of the chemical potential rules out the existence of electronic phase separation in the sample. Using valence band photoemission, we have demonstrated the formation of a low density of states at the near Fermi level electronic spectrum of SrTiO3-delta. The gap-states were observed by spectral weight transfer over a large energy scale of the stoichiometric band gap of SrTiO3 system leading finally to an insulator-metal transition. We have interpreted our results from the point of structural distortions induced by oxygen vacancies.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/S AIP.
Subjects:	Physics
Divisions:	UNSPECIFIED
Depositing User:	Dr. Rajpal Walke
Date Deposited:	17 Sep 2015 06:09
Last Modified:	17 Sep 2015 06:09
URI:	http://npl.csircentral.net/id/eprint/1197

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