Role of pO2 and film microstructure on the memristive properties of La2NiO4+δ/LaNiO3−δ bilayers

Abstract

LaNiO₃/La₂NiO₄ bilayers deposited at varying pO₂ conditions resulted in remarkable differences in film microstructure and cell parameters, directly affecting the electrical behaviour of Pt/LaNiO₃/La₂NiO₄/Pt devices. The devices deposited at low pO₂ showed the largest memristance. We propose this is due to the formation of a p-type Schottky contact between LaNiO₃ and La₂NiO₄, where the extent of its carrier depletion width can be modulated by the electric-field induced drift of interstitial oxygen ions acting as mobile acceptor dopants in La₂NiO₄.