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[en] Recently, transparent memory would be useful in invisible electronics. In this work, for the first time we present a feasibility of stable unipolar resistive switching (RS) characteristics with reset current of sub-micron ampere for the fully transparent ITO/oxygen-doped ITO/ITO memory capacitors, i.e., all ITO structures, produced by sputtering method, which shows a high optical transmittance of approximately 80% in the visible region as well as near ultra-violet region. In addition, in a RS test to evaluate a reliability for the proposed memory devices, we observed a stable endurance of >100 cycles and a retention time of >104 s at 85 °C, with a current ratio of ∼102 to ∼103. This result indicates that this transparent memory by engineering the amount of oxygen ions within the ITO films could be a milestone for future see-through electronic devices. - Highlights: • The resistive switching characteristics of the transparent ITO/O-doped ITO/ITO RRAM cells have investigated. • All ITO-based RRAM cell is achieved using oxygen doping method. • Good endurance and long retention time were observed.
[en] We report on Mg and Si isotope data of 86 presolar silicate grains identified through NanoSIMS oxygen ion imaging in thin sections of carbonaceous and ordinary chondrites. The O, Mg, and Si isotope data of 106 presolar silicates (including grains studied previously by our group) suggest division of O isotope Group 1 grains into four subpopulations: (i) “normal,” (ii) 25Mg-rich, (iii) 26Mg-rich, and (iv) 25Mg-poor. Normal Group 1 grains (∼60% of Group 1 grains) formed in the winds of low-mass asymptotic giant branch (AGB) stars, with Mg and Si defining linear arrays with slopes of ∼0.9 and 1.37, respectively, in three-isotope representations, most likely representing Galactic chemical evolution (GCE). The 25Mg-rich grains (∼25%) show enrichments in 25Mg of up to a factor 2.4 relative to solar composition and most likely formed in supernova (SN) ejecta or the winds of intermediate-mass AGB stars. The 26Mg-rich and 25Mg-poor Group 1 grains lie below the Mg GCE line and their isotopic compositions favor origins from supergiants or SNe. The O isotope Group 2 grains show a wide range of Mg-isotopic compositions, similar to Group 1 grains, with likely origins from massive AGB stars, super-AGB stars, supergiants, and SNe. The Mg- and Si-isotopic compositions of Group 4 grains are compatible with previously proposed SN origins. Our results suggest that >30% of presolar silicates formed in the winds of supergiants and in SN ejecta, and that low-mass AGB stars appear to have contributed only some 50% to presolar silicates, less than previously thought.
[en] The research on charge-ordered (CO) stripes in 214-type cobaltates/nickelates has become a fertile territory of research in the last two decades after they were experimentally evidenced in homologous superconducting cuprates LaSrCuO. Although contentious, fluctuation of such organized quantum mater e.g. stripe is believed to be responsible for high-Tc superconductivity. What still remains poorly discussed, is the influence of nonstoichiometric interstitial oxygen (Oint) on the organization of holes in a line shape. We have investigated CO state in PrSrNiO by several synchrotron and neutron diffraction measurements. PrSrNiO being a potential O-ion conductor, the high mobility of Oint gives rise to a complex long-range O-ordering even at RT. Investigating different doping level, we have found that the spacing in between the stripes is defined by the Oint-ordered supercell. I will present the relation between O-order and CO and the effect on CO correlation.
[en] Complete text of publication follows. Near-simultaneous all-sky (180deg field of view) observations of the OI 630.0 nm and OI 777.4 nm nightglow emissions are being carried out on a routine basis at 'Laboratorio Nacional de Astrofisica - LNA', Brazopolis (22.5deg S, 45.6deg W; dip latitude 17.5deg S; altitude 1860 m), Brazil, since September 2002. The all-sky imaging observations of the OI 630.0 nm and OI 777.4 nm emissions, which arise from the dissociative recombination of O2+ ions and radiative recombination of O+ ions (mainly), respectively, are used to monitor the morphology and dynamics of equatorial F-region at the respective emission heights. In this paper we present and discuss the first observations showing detached equatorial F-region plasma depletions or bubbles. Three cases are presented from observations during the years 2002 and 2003. We suggest a possible mechanism for their generation.
[en] Ionic liquid electrolytes are gaining widespread application as a gate dielectric used to control ion transport in functional materials. This letter systematically examines the important influence that device geometry in standard “side gate” 3-terminal geometries plays in device performance of a well-known oxygen ion conductor. We show that the most influential component of device design is the ratio between the area of the gate electrode and the active channel, while the spacing between these components and their individual shapes has a negligible contribution. Finally, these findings provide much needed guidance in device design intended for ionotronic gating with ionic liquids.
[en] We have considered the ionosphere as a single layer, whose ionization density and temperature increase with the height. The drift velocity of energy u and the ratio c/u proportional to the apparent height measured on the ionograms have been computed. We have also analysed the coupling of the waves to the negative labile molecular ions of oxygen (NLMIO) and have established two mechanisms for this coupling. It was proved that in the ionosphere there are regions in which the NLMIO are built up with maximum likelihood. The existence of ionospheric channels around wave frequencies twice or three times greater than the critical frequencies has been explained. (author)
[en] Reduction in polarization dependent loss of a planar lightwave circuit was achieved by asymmetric birefringence formed by ion implantation, in which oxygen ions were implanted along a diagonal of a cross-section of the planar lightwave circuit. The induced birefringence has a slow axis along the line perpendicular to the diagonal. In the present research, a decrease in polarization dependent loss of up to 3.7 dB was obtained, indicating that the method is effective for reducing polarization dependent loss.