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Epsilon‐Negative Carbon Aerogels with State Transition from Dielectric to Degenerate Semiconductor.
- Source :
- Advanced Electronic Materials; Mar2021, Vol. 7 Issue 3, p1-8, 8p
- Publication Year :
- 2021
-
Abstract
- Aerogels with negative parameters have become a research hotspot since the discovery of negative Poisson's ratio and negative thermal expansion coefficient in aerogels. The negative parameters are originally brought up and studied in electromagnetic metamaterials, leaving a question that whether aerogels can be used to construct metamaterials with negative electromagnetic parameters. Here, the authors show that negative permittivity (epsilon‐negative) property can be achieved in carbon aerogels, and its value is adjusted continuously by changing the composition of carbon aerogels but keeping their microstructure unchanged. This is a novel strategy different from the typical array‐structure‐containing metamaterials. Moreover, a physical state transition is found when increasing the carbonization temperature, where the initial low‐loss dielectric state evolves into a high‐loss one upon increasing the temperature from 400 to 700 °C followed by a final degenerate semiconductor state when increasing the temperature to 800 °C and above. This work can provide a new method toward the design of electromagnetic metamaterials, starting by choosing the component materials with optimal composition. [ABSTRACT FROM AUTHOR]
- Subjects :
- AEROGELS
POISSON'S ratio
DIELECTRICS
SEMICONDUCTORS
THERMAL expansion
Subjects
Details
- Language :
- English
- ISSN :
- 2199160X
- Volume :
- 7
- Issue :
- 3
- Database :
- Complementary Index
- Journal :
- Advanced Electronic Materials
- Publication Type :
- Academic Journal
- Accession number :
- 149219517
- Full Text :
- https://doi.org/10.1002/aelm.202000877