Study of resistive switching and magnetism modulation in the Pt/CoFe2O4/Nb:SrTiO3 heterostructures

Abstract

CoFe2O4 (CFO) thin films are epitaxially grown on Nb doped (001) SrTiO3 (NSTO) single-crystal substrates by pulsed laser deposition to form Pt/CFO/NSTO heterostructures. These heterostructures exhibit typical bipolar resistive switching effect with maximum switching ratio of 5 × 104, multi-level resistance states, excellent retention, and anti-fatigue properties. When the resistance states of the heterostructures are switched between low resistance state and high resistance state upon applying bias voltages, the saturation magnetization of the CFO films shows corresponding changes associated with the resistive switching. These close correlations between the resistive switching and the magnetization can be attributed to the electrons filling into and releasing from the defect energy levels introduced by oxygen vacancies in the CFO film. These results show potential application in the multi-functional magnetoelectric sensor and non-volatile multi-level resistive switching memory.