Letter | Published:

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

Nature Materials volume 4, pages 593596 (2005) | Download Citation



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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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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  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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The authors declare no competing financial interests.

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Correspondence to David W. Reagor.

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