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Magnétoélectricité dans les nanocomposites granulaires : analyse micro-onde

Abstract : The idea that we developed in this work is to use an electric field to control the dielectric and magnetic properties of nanomaterials in a microwave device. For this, we seek to exploit the concept of the magnetoelectric effect (ME effect). Granular nanostructures have many advantages over ceramics, thin layers and single-phase materials. The low conductivity, the absence of interdiffusion and chemical reactions parasites due to sintering, the absence of substrate, the conservation of the nanoscale, the ease and low cost protocol for developing these NCs make them materials of choice for the achievement of a ME to propose original microwave devices. We demonstrate large increases of the real and imaginary parts of the microwave effective complex permittivity of a series of (piezoelectric)BaTiO3 / (magnetostrictive) Ni nanocomposites under the action of a magnetic field, by about 10% at 2 kOe and 300% at 5 kOe, respectively. We suggest that the magnetic field dependence of the effective permittivity is consistent with a magnetoelectric effect which can be qualitatively understood within a model in which the piezoelectric phase is mechanically coupled to the magnetostrictive phase.
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https://tel.archives-ouvertes.fr/tel-00613942
Contributor : Vincent Castel <>
Submitted on : Monday, August 8, 2011 - 11:08:33 AM
Last modification on : Friday, October 23, 2020 - 4:59:20 PM
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  • HAL Id : tel-00613942, version 1

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Vincent Castel. Magnétoélectricité dans les nanocomposites granulaires : analyse micro-onde. Matière Condensée [cond-mat]. Université de Bretagne occidentale - Brest, 2009. Français. ⟨tel-00613942⟩

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