The last years have witnessed major advancements in all-electrical doping control on cuprates. In the vast majority of cases, the tuning of charge carrier density has been achieved via electric eld eect by means of either a ferroelectric polarization or by using a dielectric or electrolyte gating. Unfortunately, these approaches are constrained to rather thin superconducting layers and require large electric elds in order 1 to ensure sizable carrier modulations. In this work, we focus on the investigation of oxygen doping in an extended region through current-stimulated oxygen migration in YBa 2 Cu 3 O 7−δ superconducting bridges. The underlying methodology is rather simple and avoiding sophisticated nanofabrication process steps and complex electronics. A patterned multiterminal transport bridge conguration allows us to electrically assess the directional counterow of oxygen atoms and vacancies. Importantly, the emerging propagating front of current-dependent doping δ is probed in situ by optical microscopy and scanning electron microscopy. The resulting imaging techniques, together with photo-induced conductivity and Raman scattering investigations reveal an inhomogeneous oxygen vacancy distribution with a controllable propagation speed permitting us to estimate the oxygen diusivity. These ndings provide direct evidence that the microscopic mechanism at play in electrical doping of cuprates involves diusion of oxygen atoms with the applied current. The resulting ne control of the oxygen content would permit a systematic study of complex phase diagrams and the design of electrically addressable devices.

Increased energy efficiency spin-torque switching of magnetic tunnel junction devices with a higher order perpendicular magnetic anisotropy Applied Physics Letters 114, 012404 (2019);

HighlightsThe antioxidant effects of curcumin lysinate complexed with two cyclodextrins were compared.NDS27 is complexed with hydroxypropyl-β- and NDS28 with γ-cyclodextrin.NDS27 but not NDS28 inhibits translocation and activity of PKCδ and NADPH oxidase.NDS27 but not NDS28 improved the release of curcumin lysinate and its exchange with membrane lipids.NDS27 is a good candidate molecule to inhibit ROS production by neutrophils.

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Non-volatile resistive memory cells are promising candidates to tremendously impact the further development of Boolean and neuromorphic computing. In particular, nanoscale memory-bit cells based on electromigration (EM)-induced resistive switching in monolithic metallic structures have been identified as an appealing and competitive alternative to achieve ultrahigh density while keeping straightforward manufacturing processes. In this work, we investigate the EM-induced resistance switching in indented Al microstrips. In order to guarantee a large switching endurance, we limited the on-to-off ratio to a minimum readable value. Two switching protocols were tested, (i) a variable current pulse amplitude adjusted to ensure a precise change of resistance, and (ii) a fixed current pulse amplitude. Both approaches exhibit an initial training period where the mean value of the device's resistance drifts in time, followed by a more stable behavior. Electron microscopy imaging of the devices show irreversible changes of the material properties from the early stages of the switching process. High and low resistance states show retention times of days and endurances of ∼10 3 switching cycles.