37,939 research outputs found

    Superior removal of arsenic from water with zirconium metal-organic framework UiO-66

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    10.1038/srep16613Scientific Reports51661

    A metal–organic framework/α-alumina composite with a novel geometry for enhanced adsorptive separation

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    The development of a metal–organic framework/α-alumina composite leads to a novel concept: efficient adsorption occurs within a plurality of radial micro-channels with no loss of the active adsorbents during the process. This composite can effectively remediate arsenic contaminated water producing potable water recovery, whereas the conventional fixed bed requires eight times the amount of active adsorbents to achieve a similar performance

    Fermions and Type IIB Supergravity On Squashed Sasaki-Einstein Manifolds

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    We discuss the dimensional reduction of fermionic modes in a recently found class of consistent truncations of type IIB supergravity compactified on squashed five-dimensional Sasaki-Einstein manifolds. We derive the lower dimensional equations of motion and effective action, and comment on the supersymmetry of the resulting theory, which is consistent with N=4 gauged supergravity in d=5d=5, coupled to two vector multiplets. We compute fermion masses by linearizing around two AdS5AdS_{5} vacua of the theory: one that breaks N=4 down to N=2 spontaneously, and a second one which preserves no supersymmetries. The truncations under consideration are noteworthy in that they retain massive modes which are charged under a U(1) subgroup of the RR-symmetry, a feature that makes them interesting for applications to condensed matter phenomena via gauge/gravity duality. In this light, as an application of our general results we exhibit the coupling of the fermions to the type IIB holographic superconductor, and find a consistent further truncation of the fermion sector that retains a single spin-1/2 mode.Comment: 43 pages, 2 figures, PDFLaTeX; v2: added references, typos corrected, minor change

    Improved charge-trapping properties of HfYON film for nonvolatile memory applications in comparison with HfON and Y 2O 3 films

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    The charge-trapping properties of HfYON film are investigated by using the Al/HfYON/SiO 2/Si structure. The physical features of this film were explored by transmission electron microscopy and x-ray photoelectron spectroscopy. The proposed device shows better charge-trapping characteristics than samples with HfON or Y 2O 3 as the charge-trapping layer due to its higher trapping efficiency, as confirmed by extracting their charge-trap centroid and charge-trap density. Moreover, the Al/Al 2O 3/HfYON/SiO 2/Si structure shows high program speed (4.5 V at 14 V, 1 ms), large memory window (6.0 V at 14 V, 1 s), and good retention property, further demonstrating that HfYON is a promising candidate as the charge-trapping layer for nonvolatile memory applications. © 2011 American Institute of Physics.published_or_final_versio

    Fabrication and electrical characterization of MONOS memory with novel high-κ gate stack

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    A novel high-κ gate stack structure with HfON/SiO 2 as dual tunneling layer (DTL), AIN as charge storage layer (CSL) and HfAIO as blocking layer (BL) is proposed to prepare the charge-trapping type of MONOS non-volatile memory device by employing in-situ sputtering method. The memory window, program/erase and retention properties are investigated and compared with similar gate stack structure with Si 3N 4/SiO 2 as DTL, HfO 2 as CSL and Al 2O 3 as BL. Results show a large memory window of 3.55 V at PIE voltage of +8 V/-I5 V, high program/erase speed and good retention characteristic can be achieved using the novel Au/ HfAIO/AIN/(HfON/SiO 2)/Si gate stack structure. The main mechanisms lie in the enhanced electron injection through the high-κ HfON/SiO 2 DTL, high trapping efficiency of the high-κ AIN material and effective blocking role of the high-κ HfAIO BL. ©2009 IEEE.published_or_final_versionThe IEEE International Conference on Electron Devices and Solid-State Circuits (EDSSC) 2009, Xi'an, China, 25-27 December 2009. In Proceedings of EDSSC, 2009, p. 521-52

    Interface-state-induced degradation of GIDL current in n-MOSFETsunder hot-carrier stress

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    The dependence of increase in post-stress gate-induced-drain-leakage (GIDL) current in n-MOSFET's on creation of interface states (ΔDit) during hot-carrier stress with VG = 0.5 VD was investigated. An interface-trap-assisted tunneling conduction mechanism is proposed to account for the increase. The stress method of VG = 0.5 VD can generate a lot of interface traps near the valence band in thermal oxide samples, which is considerably suppressed in nitrided oxide samples. From the linear relationship between increase in post-stress GIDL current and created interface-state density during hot-carrier stress, ΔDit values can be estimated.published_or_final_versio

    Nitrided SrTiO 3 as charge-trapping layer for nonvolatile memory applications

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    Charge-trapping characteristics of SrTiO 3 with and without nitrogen incorporation were investigated based on Al/ Al 2 O 3/SrTiO 3/SiO 2 /Si (MONOS) capacitors. A Ti-silicate interlayer at the SrTiO 3/SiO 2 interface was confirmed by x-ray photoelectron spectroscopy and transmission electron microscopy. Compared with the MONOS capacitor with SrTiO 3 as charge-trapping layer (CTL), the one with nitrided SrTiO 3 showed a larger memory window (8.4 V at ±10 V sweeping voltage), higher P/E speeds (1.8 V at 1 ms +8 V) and better retention properties (charge loss of 38% after 10 4s), due to the nitrided SrTiO 3 film exhibiting higher dielectric constant, higher deep-level traps induced by nitrogen incorporation, and suppressed formation of Ti silicate between the CTL and SiO 2 by nitrogen passivation. © 2011 American Institute of Physics.published_or_final_versio

    Improved performance of yttrium-doped Al 2O 3 as inter-poly dielectric for flash-memory applications

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    Yttrium-doped Al 2O 3Y xAl yO) with different yttrium contents prepared by co-sputtering method is investigated as the inter-poly dielectric (IPD) for flash memory applications. A poor SiO 2-like interlayer formed at the IPD/Si interface is confirmed by X-ray photoelectron spectroscopy, and can be suppressed by Y doping through the transformation of silica into silicate. Compared with Al 2O 3 and Y 2O 3 films, the optimized Y xAl yO film shows lower interface-state density, lower bulk charge-trapping density, higher dielectric constant, and smaller gate leakage, due to the suppressed interlayer and good thermal property ascribed to appropriate Y and Al contents in the film. Therefore, the optimized Y xAl yO film is a promising candidate as the IPD for flash memory. © 2010 IEEE.published_or_final_versio
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