학술논문
Microwave Frequency-Domain Spectroscopy of Complex Heterogeneous Nanocomposites: The Electromagnetic Functionality.
Document Type
Article
Author
Source
Subject
*MAGNETIC permeability
*NANOSTRUCTURED materials
*NICKEL
*ZINC oxide
*APPROXIMATION theory
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Language
ISSN
0038-7010
Abstract
We present systematic effective permeability measurements of nanostructured granular systems composed of magnetic (Ni) grains embedded in a nonmagnetic (ZnO) matrix using broadband microwave spectroscopy. Using the transmission/reflection waveguide method, the effective complex permeability was measured in the frequency range 0.01-10 GHz. From the data collected, it is found that a mean-field approach (effective medium approximation) is appropriate for understanding the permeability of composite materials characterized by submicrometer inclusion length scales. A systematic study of the room temperature effective permeability tensor of these composite samples is performed and provides a signature for the nonreciprocity of wave propagation in these nanostructures. [ABSTRACT FROM AUTHOR]