The transmission character of BaTiO₃ ER fluids under the electric field and microwave

The perpendicular and paralleling relationships of the direction of microwave propagation and the particle chains in ER fluids were considered, respectively. The behavior of microwave propagation in BaTiO₃ ER fluids was studied. It is found that the transmittance in the fluids could be adjusted under external electric field. In the perpendicular condition, the transmittance decreases with field intensity when the concentration of the fluid is low. The amplitude of transmittance can increase with the concentration of the fluid. When the concentration exceeds a critical value, the transmittance decreases first, then increases with field intensity, there is a minimum value of the transmittance. In the paralleling condition, the transmittance decreases with electric intensity. Moreover, the behavior of microwave transmission displays the delaying character. With the increasing of field intensity, the delaying character weakens.