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arXiv · 1507.01557

Gigahertz Dielectric Polarization of Single-atom Niobium Substituted in Graphitic layers

Xuefeng Zhang·Junjie Guo·Pengfei Guan·Gaowu Qin·Stephen J. Pennycook
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Abstract

We have synthesized two Nb@C composites with an order of magnitude difference in the density of single-atom niobium substituted into graphitic layers. The concentration and sites of single-atom Nb are identified using aberration-corrected scanning transmission electron microscopy and density functional theory. Comparing the complex permittivity spectra show that the representative dielectric resonance at ~16 GHz originates from the intrinsic polarization of single-atom Nb sites, confirmed by theoretical simulations. The single-atom dielectric resonance represents the physical limit of the electromagnetic response of condensed matter, and thus might open up a new avenue for designing electromagnetic wave absorption materials. Single-atom resonance also has important implications in understanding the correlation between the macroscopic dielectric behaviors and the atomic-scale structural origin.

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Xuefeng Zhang, Junjie Guo, Pengfei Guan, Gaowu Qin, Stephen J. Pennycook. 2015-07-06. Gigahertz Dielectric Polarization of Single-atom Niobium Substituted in Graphitic layers. https://arxiv.org/abs/1507.01557

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