Motivation Experimental method Results Conclusion References Resistive switching effects on Fe3O4 grown on vicinal substrates: effect of the stepped morphology on the switching phenomena. Askar Syrlybekov1 , Ozhet Mauit1, Sumesh Sofin1, Elisabetta Arca1, Igor Shvets1 Cleaner Energy Lab, School of Physics, Trinity College Dublin, Dublin 2, Ireland Motivation Experimental method XRD Magnetite (Fe3O4) undergoes a transition at Verwey transition (TV) at 120K (from a high-temperature conducting phase to a low-temperature insulating phase). Epitaxial Fe3O4 films grown on MgO are known to suffer from the formation of antiphase boundaries (APBs) which grow preferentially align parallel to step edges Template preparation Single crystal vicinal (4˚ miscut) MgO (100) substrate with a miscut direction of <001> was annealed at 1200˚C for 3 hours in air in a high temperature furnace Thin film preparation Fe3O4 was grown by PA-MBE system (DCA MBE M600, Finland) in an oxygen partial pressure of 1×10-5 Torr at 600C 4 Point Probes were deposited by E-Beam lithography Pronounced electrically driven hysteretic switching of the electronic conductance are observed once sample temperatures are reduced below TV. The transition is not the result of local heating above TV, but is an electrically driven breakdown of the insulating state XPS In all our experiments, a planar geometry of the contact is used . Characterization Atomic Force microscope X-ray diffraction DC electrical properties PLD Aim of the study: prepare template with suitable morphology in order to control the concentration of defects (APBs) and assess their effect on the switching characteristics Lamella for TEM Results Resistance switching characterization Template preparation Step-bunching of monocrystalline miscut MgO substrates in an alumina tube furnace Tuning the temperature and miscut angle allows tuning the frequency of the steps and the steps height Al contaminations coming from the tube furnace act as the driving nucleation mechanism for the bunching process Film depositions and patterning RS behaviour along the steps (AS) as a function of temperature Epitaxial films were grown on MgO substrates. On flat samples, films are strained. On vicinal substrates, the films are still epitaxial (Figure c) and tend to follow the morphology of the substrate (Figure d) Cycles at a given temperature (95K) 4 Point Probe were deposited by on the sample both along the steps (AS) and perpendicularly to the steps. The distance between the inner probe is 200 nm whereas between the outer is 1mm Voltage is applied between the outer probes while current is measure between the inner two. RS behaviour along the steps requires slightly lower switching voltages and a much larger number of cycles can be achieved. Conclusion Hysteresis in the I-V curves of magnetite grown on a stepped MgO surfaces below the Verwey transition temperature (T<TV) Anisotropic resistive switching by applying electric field along the steps and perpendicular to the steps Along the steps, stable RS behaviour was observed (more than 16000 cycles at 95 K without damage or degradation) References Acknowledgments Financial support from Science Foundation Ireland under grant SFI12/IA/1264 is gratefully acknowledged