Reversible transition of filamentary and ferroelectric resistive switching in BaTiO3/SmNiO3 heterostructures
Recently, resistive switching (RS) phenomena have been widely studied for promising properties which are favorable to be implemented in next generation information technologies. However, devices with multi resistance states originated from different mechanisms, which are desirable for applications, have seldom been reported. In current work, a coexistence of clockwise and counterclockwise RS behaviors have been found in BaTiO3/SmNiO3 (BTO/SNO) heterostructures, which were fabricated by pulse laser deposition. The mechanisms underneath the two RS behaviors were demonstrated to be barrier profile modulation due to ferroelectric polarization reversal and conducting filament forming/deforming due to migration of VO, respectively. Tri-nonvolatile resistance states have been clearly observed, and reversible transition between them has been confirmed. Furthermore, preliminary simulation of synapse characteristics, paired-pulse facilitation and paired-pulse depression, were realized by only varying the electric stimulation voltage amplitude but not the polarity. Our findings reported here shed new light on designing next generation novel devices.