Optical Properties of (SrMnO3)n/(LaMnO3)2n superlattices: an insulator-to-metal transition observed in the absence of disorder

Abstract

We measure the optical conductivity of (SrMnO3)n/(LaMnO3)2n superlattices (SL) for n=1,3,5, and 8 and 10 < T < 400 K. Data show a T-dependent insulator to metal transition (IMT) for n \leq 3, driven by the softening of a polaronic mid-infrared band. At n = 5 that softening is incomplete, while at the largest-period n=8 compound the MIR band is independent of T and the SL remains insulating. One can thus first observe the IMT in a manganite system in the absence of the disorder due to chemical doping. Unsuccessful reconstruction of the SL optical properties from those of the original bulk materials suggests that (SrMnO3)n/(LaMnO3)2n heterostructures give rise to a novel electronic state.

Published Online in Nano Letters, November 8, 2010; http://pubs.acs.org/doi/abs/10.1021/nl1022628; 5 pages, 3 figures

References in corpus (6)

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• A Microscopic View on the Mott transition in Chromium-doped V2O3
• Electronic reconstruction at SrMnO3-LaMnO3 superlattice interfaces
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• Optical conductivity of V4O7 across its metal-insulator transition
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