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Highly conductive nanolayers on strontium titanate produced by preferential ion-beam etching

Nature Materials volume 4, pages 593–596 (2005)Cite this article

Abstract

Developing fabrication methods for electronically active nanostructures is an important challenge of modern science and technology. Fabrication efforts1,2,3,4 for crystalline materials have been focused on state-of-the-art epitaxial growth techniques. These techniques are based on deposition of precisely controlled combinations of various materials on a heated substrate. We report a method that does not require deposition and transforms a nanoscale layer of a complex crystalline compound into a new material using low-energy ion-beam preferential etching (IBPE). We demonstrate this method by transforming a widely used5,6,7,8,9,10 insulator model system, SrTiO3, into a transparent conductor. Most significantly, the resistivity decreases with decreasing temperature as ∼T2.5±0.3 and eventually falls below that of room-temperature copper. These transport measurements imply a crystal quality in the conduction channel comparable to that obtained1 with the highest-quality growth techniques. The universality of low-energy IBPE implies wide potential applicability to fabrication of other nanolayers.

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Figure 1: Photographs of a double-sided polished SrTiO3 sample ion-bombarded on the left half.
Figure 2: Two-probe resistance versus ion-beam exposure time.
Figure 3: Four-probe resistivity versus temperature for several samples.
Figure 4

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Acknowledgements

The authors would like to thank J. B. Chlistunoff, I. Campbell, T. Kimura and X. Gao for their help. This work was supported by the US Department of Energy.

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Authors and Affiliations

  1. Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, USA

    David W. Reagor

  2. Brookhaven National Laboratory, Upton, New York, 11973, USA

    Vladimir Y. Butko

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  1. David W. Reagor
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Correspondence to David W. Reagor.

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Reagor, D., Butko, V. Highly conductive nanolayers on strontium titanate produced by preferential ion-beam etching. Nature Mater 4, 593–596 (2005). https://doi.org/10.1038/nmat1402

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