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TT: Fachverband Tiefe Temperaturen

TT 35: CE: Low-dimensional Systems - Materials 3

TT 35.16: Vortrag

Mittwoch, 16. März 2011, 18:30–18:45, HSZ 301

Nanogranular Metals: From electronic correlations to strain-sensing applications — •Christian H. Schwalb^1,2 and Michael Huth¹ — ¹Physikalisches Institut, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany — ²NanoScale Systems GmbH, Robert-Bosch-Str. 7, 64293 Darmstadt, Germany

Granular metals are artificial materials in which a conducting phase made of metallic nanoparticles is (randomly) dispersed into an insulating matrix. The charge transport in such systems is dominated by tunneling between neighboring metallic nanoparticles, a process that is strongly influenced by correlation effects. These fundamental processes can be used for practical applications, since the tunnel coupling has an intrinsically exponential dependence on the inter-grain distance that is altered under strain.

In this work, we present a novel methodology for strain-sensing based on nanogranular metals using focused electron-beam-induced deposition (FEBID). The gauge factor for these nanogranular metals depends on the conductivity of the sensor element that can be altered by electron-beam irradiation leading to a distinct maximum in the sensitivity that can be attributed to a persistent change of the dielectric carbon matrix.[1] Additionally an analysis scheme is presented that draws on recent advances in the understanding of charge transport mechanisms in granular metals [2] and allows for a semi-quantitative description of the sensitivity of granular metal based strain sensors.
C. H. Schwalb et al., Sensors 10, 9847 (2010)
M. Huth, J. Appl. Phys. 107, 113709 (2010)