Giant resistive switching effects in symmetric all-oxide tunnel junctions with La 2/3 Sr 1/3 MnO 3 electrodes

Ferroelectric tunnel junctions have opened up promising routes towards energy-efficient data storage applications and memristive devices [1]. Polarization reversal in a ferroelectric tunnel barrier can change the electrical resistance of a junction, a phenomenon known as tunneling electroresistance (TER). On the other hand, redox-based effects such as the migration of oxygen vacancies can cause large resistive switching in transition metal oxides [2]. Here, we demonstrate nearly identical switching behavior in nominally symmetric tunnel junctions that are comprised of two La 2/3 Sr 1/3 M-nO 3 (LSMO) electrodes separated by a ferroelectric PbZr 0.2 Ti 0.8 O 3 (PZT) or BaTiO 3 (BTO) tunnel barrier, or a paraelectric SrTiO 3 (STO) tunnel barrier. The tunnel junctions were grown by pulsed laser deposition and patterned into solid junctions with a lateral dimension of 20 × 40 μm 2 , 30 × 60 μm 2 , and 40 × 80 μm 2 . Moreover, LSMO/PZT and LSMO/BTO bilayer were patterned into Hall bar structures for in-plane electric transport measurements inside a scanning probe microscope.