Reversible and reproducible giant universal electroresistance effect

After the prediction of the giant electroresistance effect, much work has been carried out to find this effect in practical devices. We demonstrate a novel way to obtain a large electroresistance (ER) effect in the multilayer system at room temperature. The current-in-plane (CIP) electric transport measurement is performed on the multilayer structure consisting of (011)-Pb(Mg_1/3Nb_2/3)O₃-PbTiO ₃(PMN-PT)/Ta/Al-O/metal. It is found that the resistance of the top metallic layer shows a hysteretic behavior as a function electric field, which corresponds well with the substrate polarization versus electric field (P - E) loop. This reversible hysteretic R - E behavior is independent of the applied magnetic field as well as the magnetic structure of the top metallic layer and keeps its memory state. This novel memory effect is attributed to the polarization reversal induced electrostatic potential, which is felt throughout the multilayer stack and is enhanced by the dielectric Al-O layer producing unique hysteretic, reversible, and reproducible resistance switching behavior. This novel universal electroresistance effect will open a new gateway to the development of future multiferroic memory devices operating at room temperature.