Morphology control of Ce-doped SnO2 and enhanced microwave absorbing performance at 2−18 GHz

Abstract

Semiconductor metal oxides are widely used in the field of wave absorption because of their easily tunable dielectric properties. Doping or modulating the morphology has been demonstrated to be an effective method to improve the microwave (MW) absorbing performance of semiconductor metal oxides. In this study, Ce-doped SnO2 was prepared by a simple and effective coprecipitation method. Single-crystal SnO2 nanorods were generated during the doping process and the size of the nanorods could be controlled by modifying the concentration of Ce. The presence of nanorods greatly enhances the MW absorbing performance: when the doping molar ratio is 3%, the minimum reflection loss of the absorber is −77.91 dB at a frequency of 13.79 GHz with a thickness of 1.6 mm and the maximum effective absorbing bandwidth is 4.47 GHz at a thickness of 1.5 mm. Excellent MW absorbing performance of Ce-doped SnO2 is attributed to its excellent impedance matching and interfacial polarization.