Role of pO(2) and film microstructure on the memristive properties of La2NiO4+delta/LaNiO3-delta bilayers

LaNiO3/La2NiO4 bilayers deposited at varying pO(2) 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 pO(2) 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.