Tunneling-Induced Negative Permittivity in Ni/MnO Nanocomposites by a Bio-gel Derived Strategy
The one-dimensional wires are the most common building blocks in metamaterials. In this work, the zero-dimension nanoparticles connected by tunneling effects were used to construct the metamaterials, which provided a more flexible alternative for designing the geometrical configuration of metamaterials, especially in nanodevices. The composites with nickel nanoparticles @ MnO were prepared by a bio-gel derived strategy. Nickel nanoparticles were not connected geometrically, but the conductive network had been already formed, which was a tunneling-dominated percolative phenomenon demonstrated by the first-principles calculation. Negative permittivity was achieved in the composites, as the low-frequency plasmonic state could be generated in the tunneling nickel-networks, at the same time, the negative susceptibility was observed due to the diamagnetism of the tunneling current loops. Electromagnetic simulation indicates that the composites have the potential for electromagnetic shielding (only 0.25 mm in thickness). It is believed that this work not only fills up the research gap in the influence of tunneling effect on negative electromagnetic parameters but also opens up another way of preparing metamaterials by using zero-dimension nanoparticles instead of one-dimension wires.
- This article is part of the themed collection: Journal of Materials Chemistry C HOT Papers