1. Dimensionality Control of d-orbital Occupation in Oxide Superlattices.
- Author
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Da Woon Jeong, Woo Seok Choi, Satoshi Okamoto, Jae-Young Kim, Kyung Wan Kim, Soon Jae Moon, Deok-Yong Cho, Ho Nyung Lee, and Tae Won Noh
- Subjects
TRANSITION metal oxides ,SUPERLATTICES ,SPECTRUM analysis ,SEMICONDUCTORS ,ELECTRONIC equipment ,PHOTOCATALYSIS ,ELECTRONIC data processing ,ELECTRONIC materials - Abstract
Manipulating the orbital state in a strongly correlated electron system is of fundamental and technological importance for exploring and developing novel electronic phases. Here, we report an unambiguous demonstration of orbital occupancy control between t
2g and eg multiplets in quasi-two-dimensional transition metal oxide superlattices (SLs) composed of a Mott insulator LaCoO3 and a band insulator LaAlO3 . As the LaCoO3 sublayer thickness approaches its fundamental limit (i.e. one unit-cell-thick), the electronic state of the SLs changed from a Mott insulator, in which both t2g and eg orbitals are partially filled, to a band insulator by completely filling (emptying) the t2g (eg ) orbitals. We found the reduction of dimensionality has a profound effect on the electronic structure evolution, which is, whereas, insensitive to the epitaxial strain. The remarkable orbital controllability shown here offers a promising pathway for novel applications such as catalysis and photovoltaics, where the energy of d level is an essential parameter. [ABSTRACT FROM AUTHOR]- Published
- 2014
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