Abstract
Large-scale β-MnO 2/SiO 2 core-shell nanorods were synthesized by hydrolysis process. The product was characterized by XRD, EDS, SEM and TEM. The thickness of the SiO 2 shell layer is about 3 nm∼5 nm, which can be tuned by changing the amount of tetraethyl orthosilicate (TEOS) and the reaction time. The dielectric properties of the synthesized core-shell nanorods at the temperature range from 373 K to 773 K in X-band were investigated in detail and the mechanism of the dielectric response was discussed. The dielectric loss of the SiO 2-coated MnO 2 nanorods at 773 K was about twice than that at 373 K. The high dielectric loss is mainly attributed to the interfacial polarization and the electromagnetic impedance match between the SiO 2 shell layer and MnO 2 core layer. The quantitative formula between the permittivity of β-MnO 2/SiO 2 core-shell nanorods and the thickness of the SiO 2 shell is established, which can be used to tune the dielectric properties of the core-shell nanorods through controlling the thickness of the SiO 2 shell layer.
| Original language | English |
|---|---|
| Pages (from-to) | 6953-6958 |
| Number of pages | 6 |
| Journal | Journal of Nanoscience and Nanotechnology |
| Volume | 11 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - Aug 2011 |
Keywords
- Electromagnetic impedance
- High-temperature dielectric properties
- Interfacial polarization
- β-MnO /SiO Core-shell nanorods