Epitaxial growth of high quality SrFeO₃ films on (001) oriented (LaAlO₃)_0.3(Sr₂TaAlO₆)_0.7

Growth of SrFeO₃ films with stoichiometry of (1:1:3) is challenging as the unstable Fe⁴⁺ oxidation state favors the formation of O vacancies. Here, we report layer by layer growth of SrFeO₃ on (001) oriented LSAT using ozone assisted molecular beam epitaxy. Upon cooling from room temperature, the film's resistivity is as low as the best single crystals, with two identifiable transition points near 110 K and 60 K in resistivity measurements, being hysteretic between cooling and warming through the 60 K transition. During various annealing steps, the low temperature resistivity changes by orders of magnitude, accompanied by an increase in the c-axis lattice parameter. The hysteresis near 60 K persists for a wide range of annealing conditions. We have identified conditions where changes due to annealing can be reversed. We attribute resistiviy and lattice changes to the reversible movement of oxygen. Thus, SrFeO3 may be a promising material for resistive memory .