Microwave absorbing properties of high titanium slag were investigated by using microwave cavity perturbation technique. High titanium slag containing more than 90% TiO2 was prepared by carbothermal reduction of ilmenite. The temperature rise curve of high titanium slag in microwave heating process was obtained. Crystalline compounds of high titanium slag before and after microwave irradiation were obtained and characterized by X-ray diffractometry (XRD). Effects of particle size of high titanium slag anal mixtures of high titanium slag with different mass fractions of V2o5 on microwave absorbing properties were investigated systematically. The results show that high titanium slag has good microwave absorption property; untreated high titanium slag mainly consists of crystalline compounds of anatase and iron titanium oxide, while the microwave-irradiation treated one is mainly composed of crystalline compounds of rutile and irgn titanium oxide. Synthetic anatase is transformed completely into rutile at about 1 050 ℃ for 20 min under microwave irradiation. High frequency shift and low amplitude of voltage make high titanium slag an ideal microwave absorbent. 180 μm of particle size and 10% mass fraction of V2O5 are found to be the optimum conditions for microwave absorption.
Numerical simulation has been performed on the optical transmission enhancement properties of a one-dimensional Ag film single slit structure with grooves. The results show that the position,depth and number of the grooves have great influence on the optical transmission,and surface plasmon polariton and resonance mode are the primary factors. The maximal extinction ratio of 35.8 dB is achieved in the single slit structure by adjusting groove depth.
YANG Jing-jingHUANG MingYU JiangSHI Ji-hongPENG Jin-hui