Open Access Nano Express

Dramatically enhanced non-Ohmic properties and maximum stored energy density in ceramic-metal nanocomposites: CaCu3Ti4O12/Au nanoparticles

Wattana Tuichai1, Saowalak Somjid1, Bundit Putasaeng2, Teerapon Yamwong2, Apiwat Chompoosor34*, Prasit Thongbai34*, Vittaya Amornkitbamrung34 and Santi Maensiri5

Author Affiliations

1 Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand

2 National Metal and Materials Technology Center (MTEC), Thailand Science Park, Pathumthani 12120, Thailand

3 Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand

4 Nanotec-KKU Center of Excellence on Advanced Nanomaterials for Energy Production and Storage, Khon Kaen 40002, Thailand

5 School of Physics, Institute of Science, Suranaree University, Nakhon Ratchasima 30000, Thailand

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Nanoscale Research Letters 2013, 8:494  doi:10.1186/1556-276X-8-494

Published: 21 November 2013


Non-Ohmic and dielectric properties of a novel CaCu3Ti4O12/Au nanocomposite were investigated. Introduction of 2.5 vol.% Au nanoparticles in CaCu3Ti4O12 ceramics significantly reduced the loss tangent while its dielectric permittivity remained unchanged. The non-Ohmic properties of CaCu3Ti4O12/Au (2.5 vol.%) were dramatically improved. A nonlinear coefficient of ≈ 17.7 and breakdown electric field strength of 1.25 × 104 V/m were observed. The maximum stored energy density was found to be 25.8 kJ/m3, which is higher than that of pure CaCu3Ti4O12 by a factor of 8. Au addition at higher concentrations resulted in degradation of dielectric and non-Ohmic properties, which is described well by percolation theory.

Nanocomposite; Dielectric permittivity; Percolation threshold; Varistor