Anomalous transient conductivity of magnetic elastomer under the action of strain and magnetic field

Magnetoactive (aka magnetorheological) elastomer composites, which are elastic polymer matrices filled with micron-sized particles of a ferromagnet, are a novel type of magnetically controllable material. In addition to their complex magnetomechanical behavior, magnetoactive elastomers, as conducting substances, possess electrical resistivity that is highly sensitive to both mechanical stress and the applied magnetic field. Here, we present a study on the response of such composites to pulse mechanical or magnetic perturbations. Remarkably, a transient electric process induced by any of those stimuli is always non-monotonic. The electric current measurements reveal that before settling at the new equilibrium level, the resistivity always undergoes a substantial jump-up independently on the sign of the perturbation: a pressure on/off or the field on/off. The main goal of the work is to register the encountered effect in detail.