High-temperature dielectric properties and enhanced temperature-response attenuation of β-MnO2 nanorods

Large-scale β-MnO2 nanorods were synthesized by the hydrothermal method. In X band, the microwave attenuation of the β-MnO2 nanorods is evidently enhanced with increasing temperature from 293 to 773 K. The enhanced temperature-response attenuation of β-MnO2 nanorods is mainly attributed to the decrease in the real permittivity and the increase in the imaginary permittivity at high temperature. The decrease in real permittivity would be mainly ascribed to the increase in the disorder degree of orientational alignment of the intrinsic polar moment in the β-MnO2 nanorods with temperature increasing. The increase in imaginary permittivity may result from the lower resistivity with rising temperature.