超声化学沉淀法制备花瓣状ZnO及其微波吸收性能

Preparation and Microwave Absorbing Properties of Flower-like ZnO by Ultrasonic Chemical Precipitation Method

采用超声化学沉淀的方法,制备花瓣状ZnO粉体。利用扫描电子显微镜和X射线衍射仪对合成粉体进行表征,矢量网络分析仪测试其在2~18 GHz频率范围的微波介电性能和微波反射系数。结果表明:当pH=10、超声化学沉淀0.5 h可以制得花瓣状的ZnO颗粒。随频率的增加,样品的介电常数实部ε′逐渐增大,虚部ε″则是先增大后减小,在6.837 GHz时达到最大,为0.18。从8 GHz开始样品对微波产生吸收,15.6 GHz时最大衰减为-3.5dB。对产生介电损耗和微波吸收的机理进行了讨论。

Flower-like zinc oxide powders were prepared by ultrasonic chemical precipitation method.The synthesised powders were characterized by scanning electron microscopy and X-ray diffraction.The dielectric parameters and microwave reflection were determined by a vector network analyzer in the range of 2-18 GHz.The results showed that the flower-like zinc oxide was obtained under the conditions of pH=10 and 0.5 h by ultrasonic chemical deposit.The real part ε′ of permittivity increases gently and the imaginary part ε″ of permittivity of the sample increases firstly and then decreases with the frequency increasing,with the maximum ε″ of 0.18 at 6.837 GHz.The microwave absorbing of the sample increases gradually at 8 GHz,with the maximum attenuation of-3.5 dB at 15.6 GHz.The mechanism of dielectric loss and microwave absorbing has been discussed.