Resistive switching in epitaxial BaTiO₃ films grown on Nb-doped SrTiO₃ by PLD

Highlights: • Bipolar RS in BTO films was attributed to the formation and rupture of conductive filaments. • XPS confirmed that oxygen vacancies play a significant role in RS of BTO films. • I–V curves of the as-prepared samples show linear Ohmic conduction at LRS and SCLC at HRS, respectively. - Abstract: 100-nm-thick epitaxial BaTiO₃ (BTO) films were prepared on the Nb-doped SrTiO₃ (NSTO) single-crystal substrates by pulsed laser deposition. Bipolar resistive switching (RS) behavior was observed in the as-prepared BTO/NSTO samples, which was attributed to the formation and rupture of conductive filaments in the BTO films. The RS effect was suppressed after the samples were annealed in air due to the decrease in oxygen vacancies during annealing, which was confirmed by X-ray photoelectron spectroscopy (XPS) measurements. The current–voltage curves of the as-prepared samples show linear ohmic conduction at the low resistive state and space-charge-limited conduction (SCLC) at the high resistive state, respectively. SCLC dominated in the annealed samples