TY - JOUR
T1 - β-MnO 2/SiO 2 core-shell nanorods
T2 - Synthesis and dielectric properties
AU - Shi, Xiaoling
AU - Cao, Maosheng
AU - Fang, Xiaoyong
PY - 2011/8
Y1 - 2011/8
N2 - 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.
AB - 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.
KW - Electromagnetic impedance
KW - High-temperature dielectric properties
KW - Interfacial polarization
KW - β-MnO /SiO Core-shell nanorods
UR - http://www.scopus.com/inward/record.url?scp=84856876291&partnerID=8YFLogxK
U2 - 10.1166/jnn.2011.4252
DO - 10.1166/jnn.2011.4252
M3 - Article
AN - SCOPUS:84856876291
SN - 1533-4880
VL - 11
SP - 6953
EP - 6958
JO - Journal of Nanoscience and Nanotechnology
JF - Journal of Nanoscience and Nanotechnology
IS - 8
ER -