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arXiv · 0708.2140

The nanostructural origin of the ac conductance in dielectric granular metals: the case study of Co_20(ZrO_2)_80

Z Konstantinovic·M Garcia del Muro·X Batlle·A Labarta·M. Varela
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Abstract

We show which is the nanostructure required in granular Co20(ZrO2)80 thin films to produce an ac response such as the one that is universally observed in a very wide variety of dielectric materials. A bimodal size distribution of Co particles yields randomly competing conductance channels which allow both thermally assisted tunneling through small particles and capacitive conductance among larger particles that are further apart. A model consisting on a simple cubic random resistance-capacitor network describes quantitatively the experimental results as functions of temperature and frequency, and enables the determination of the microscopic parameters controlling the ac response of the samples.

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Z Konstantinovic, M Garcia del Muro, X Batlle, A Labarta, M. Varela. 2007-08-16. The nanostructural origin of the ac conductance in dielectric granular metals: the case study of Co_20(ZrO_2)_80. https://doi.org/10.1063/1.2766858

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