Using the electrooptic effect to study charge relaxation in colloidal solutions of magnetite

The kinetics of birefringence in a colloidal system of magnetite particles in kerosene under the action of a pulsed electric field has been studied using an electrooptical cell with electrodes covered by a thin insulating film. Rectangular pulses of the field induce jumps in the birefringence signal (at the moments of field switching on and off), which are related to relaxation of the charge formed in the near-electrode region. Experimental data are used to evaluate the characteristic time of near-electrode space charge formation.