Adjustable character of microwave attenuation in BaTiO_3 electrorheological fluids  

作　　者：FAN Jijun ZHAO Xiaopeng HUANG Min GUAN Litao WEN Lishi 

机构地区：[1]Institute of Electrorheological Technology,141#Northwestern Polytechnical University,Xi’an710072,China [2]Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110015,China

出　　处：《Progress in Natural Science:Materials International》2002年第10期753-758,共6页自然科学进展·国际材料(英文版)

基　　金：Supported by the National Natural Science Foundation of China (Grant No. 59832090) ;the Natural Science Foundation of China for Distinguished Young Scholars (Grant No. 50025207)

摘　　要：The behavior of microwave attenuation in BaTiO3 electrorheological fluids is studied when considering microwave propagation in the directions perpendicular and parallel to the particle chains, respectively. In the former case, the microwave attenuation increases with field strength when the particle concentration is low, and the increase of the particle concentration can also increase the microwave attenuation. However, when the particle concentration exceeds a critical value, the attenuation will first increase then decrease with field strength. At the same time, the higher the field strength, the greater the change of microwave attenuation. Moreover, there is a saturation field strength. When the field strength is lower than the saturated one, the change of microwave attenuation is fast. On the other hand, in the case of microwave propagation parallel to the particle chains, the microwave attenuation increases with the field strength monotonously. In addition, the variation of microwave attenuation with the field strength shows relaxation effect. The adjustable character of microwave attenuation in BaTiO3 ER fluids can be attributed to the dielectric changes resulting from the field-induced-structural transformation and the polarization of BaTiO3.The behavior of microwave attenuation in BaTiO3 electrorheological fluids is studied when considering microwave propagation in the directions perpendicular and parallel to the particle chains, respectively. In the former case, the microwave attenuation increases with field strength when the particle concentration is low, and the increase of the particle concentration can also increase the microwave attenuation. However, when the particle concentration exceeds a critical value, the attenuation will first increase then decrease with field strength. At the same time, the higher the field strength, the greater the change of microwave attenuation. Moreover, there is a saturation field strength. When the field strength is lower than the saturated one, the change of microwave attenuation is fast. On the other hand, in the case of microwave propagation parallel to the particle chains, the microwave attenuation increases with the field strength monotonously. In addition, the variation of microwave attenuation with the field strength shows relaxation effect. The adjustable character of microwave attenuation in BaTiO3 ER fluids can be attributed to the dielectric changes resulting from the field-induced-structural transformation and the polarization of BaTiO3.

关 键 词：electrorheological fluids BATIO3 microwave attenuation relaxation effect 

分 类 号：TN015[电子电信—物理电子学]