Equilibrium orientation of an ellipsoidal particle inside a dielectric medium with a finite electric conductivity in the external electric field.

We study the stability of the orientation of an ellipsoidal dielectric particle immersed into a host dielectric medium under the action of the external electric field. It is assumed that the particle and the host medium have a finite electric conductivity. We demonstrate that an equilibrium orientation of the ellipsoidal particle changes with time in a stationary electric field with a constant direction. It was found that during time interval T1 an equilibrium orientation of the spheroidal particle with a finite electric conductivity remains the same as the equilibrium orientation of an ideal dielectric particle. During time interval T2 , where T= T1 + T2 is a period of the external electric field, the equilibrium orientation of the axis of symmetry of the particle is normal to the initial equilibrium direction.