ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Fabrication and characterization of epitaxial NbN/MgO/NbN Josephson tunnel junctions (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 90 (2001), S. 4796-4799 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We fabricated epitaxial NbN/MgO/NbN Josephson tunnel junctions with good tunneling characteristics in the range of JC=0.2–70 kA/cm2. The counter and base NbN electrodes of the tunnel junctions had the same TC and 20 K resistivity at about 15.7 K and 60 μΩ-cm, respectively. X-ray analysis showed that all the layers that formed the tunnel junctions grew epitaxially. In the range of JC=0.2–15 kA/cm2, the tunnel junctions fabricated had large gap voltages (5.6–5.9 mV), narrow gap widths (less than 0.1 mV), high ICRN products (2.6–3.8 mV), and small subgap leakage current (Vm=40–96 mV). © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1409583
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Superconducting properties and crystal structures of single-crystal niobium nitride thin films deposited at ambient substrate temperature (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 7837-7842 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Single-crystal niobium nitride (NbN) thin films were fabricated at ambient substrate temperature so that photoresist lift-off techniques could be used in fabricating Josephson tunnel junctions. In this article, we describe the superconducting properties and crystal structure of the NbN films. Even though the substrates were not heated, the NbN films had excellent superconducting properties: a high Tc of 16 K, low normal-state resistivity (ρ20=62 μΩ cm), and residual resistivity ratios RRR=ρ300/ρ20 above one. The film structures, which were investigated by x-ray diffraction, electron diffraction patterns and transmission electron micrographs, show a single-phase orientation without columnar and granular structures. We have found that the superconducting properties depend on the lattice parameter, and the best films had a lattice parameter of 0.446 nm. NbN/AlN/Nb tunnel junctions were fabricated to measure the superconducting energy gap of the NbN films. We estimated the energy gap ΔNbN to be 2.6 meV and the magnetic penetration depth λNbN to be 176 nm. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.362392
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    NbN/AlN/NbN tunnel junctions with high current density up to 54 kA/cm2 (1997)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 70 (1997), S. 114-116 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report on progress in the development of high current density NbN/AlN/NbN tunnel junctions for applications as submillimeter wave superconductor-insulator-superconductor mixers. A very high current density up to 54 kA/cm2, roughly an order of magnitude larger than any reported results for all-NbN tunnel junctions, was achieved in the junctions with about 1 nm thick AlN barriers. The magnetic field and temperature dependence of critical supercurrents were measured to investigate the Josephson tunneling behavior of critical supercurrents in the high-Jc junctions. The junctions showed high-quality junction characteristics with a large gap voltage of 5 mV and sharp quasiparticle current rise (ΔVg=0.1 mV). The Rsg/RN ratio was about 5 with a Vm value of 14 mV measured at 4.2 K. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.119279
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Submillimeter wave responses in NbN/AlN/NbN tunnel junctions (1995)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 66 (1995), S. 1992-1994 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The submillimeter wave frequency responses of NbN/AlN/NbN tunnel junctions have been investigated using quasioptical coupling techniques and an optically pumped far-infrared laser. A two junction array was integrated at the feeds of a bowtie antenna. Measurements on the junctions were made by monitoring photon-assisted tunneling steps induced in the current–voltage characteristics. These n=±1 photon steps were clearly observed with irradiation at 303, 594, 693, and 762 GHz. The results suggest it will be possible to realize submillimeter wave mixers by using these junctions. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.113672
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    High critical current density NbN/AlN/NbN tunnel junctions fabricated on ambient temperature MgO substrates (1994)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 64 (1994), S. 2034-2036 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: NbN/AlN/NbN tunnel junctions are fabricated at ambient temperature on MgO substrates, and a critical current density of 8 kA/cm2 is obtained in junctions with 1.5–nm–thick AlN barriers. Even though the NbN/AlN/NbN trilayers are deposited without intentional heating, the junctions show a large gap voltage (Vg=5 mV), sharp quasiparticle current rise (ΔVg=0.16 mV), and small subgap leakage current (Vm=25 mV and Rsg/RN=9). This report shows that high-quality NbN/AlN/NbN tunnel junctions can be made at ambient substrate temperature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.111730
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Quasi-optical submillimeter-wave mixers with NbN/AlN/NbN tunnel junctions (1996)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 69 (1996), S. 2435-2437 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We demonstrate low-noise heterodyne mixing with NbN/AlN/NbN tunnel junctions in the submillimeter-wave region. The prepared junction size was 1 μm in diameter and the current density was about 20 kA/cm2, supplying a small ωCJRN product (ωCJRN=3 at 300 GHz). The mixer used a lens-coupled log-period antenna and an integrated tuning circuit which incorporated a radial short stub tuner for resonating out the junction capacitance. The junctions showed good dc I–V characteristics, excellent submillimeter-wave responses and sensitive heterodyne mixing responses. From 254 to 350 GHz the average receiver noise temperature measured using the standard Y-factor method was about 250 K double sideband (DSB). The lowest receiver noise temperature, 200 K (DSB), was obtained around 303 GHz. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.117662
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Terahertz NbN/AlN/NbN mixers with Al/SiO/NbN microstrip tuning circuits (1998)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 73 (1998), S. 680-682 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have developed a low-noise quasioptical NbN/AlN/NbN superconductor-insulator-superconductor (SIS) mixer that operates at terahertz frequencies. The mixer uses a MgO hyperhemispherical lens with an antireflection cap, a single-crystal NbN log-periodic antenna, and two-junction tuning circuits which employ Al/SiO/NbN microstriplines. The NbN/AlN/NbN junction size was about 0.9 μm in diameter, and the current density was about 45 kA/cm2. The frequency dependence of the receiver noise temperature was investigated by using an optically pumped far-infrared laser and a backward-wave oscillator as a local oscillator at several frequencies from 670 to 1082 GHz. The experimental results showed that the center frequency was around 800 GHz, and the receiver noise temperature measured by the standard Y-factor method was 457 K (DSB) at 783 GHz including a 9-μm-thick Mylar beam splitter loss and other optical losses at the physical bath temperature of 4.2 K. This is the first SIS mixer based on NbN with low-noise performance (12hν/kB) above the gap frequency of Nb. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.121946
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Interface and tunneling barrier heights of NbN/AlN/NbN tunnel junctions (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 75 (1999), S. 701-703 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The tunneling barrier height of NbN/AlN/NbN tunnel junctions was measured by investigating the barrier thickness dependence of the current density, and the junction interface was studied by cross-sectional transmission electron microscopy (TEM). We found that the current density of the junctions has two distinct types of dependency on the AlN barrier thickness, corresponding to two average barrier heights in different regions for the current density. The TEM observations showed that the junctions had a very smooth and clear electrode–barrier interface, and the crystal structures of the counterelectrode NbN films were strongly dependent on the thickness of AlN barriers. The average barrier height was estimated to be 2.35 eV in the low-Jc region, Jc〈5 kA/cm2, and to be 0.88 eV in the high-Jc region, Jc〉5 kA/cm2. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.124487
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    An aspartic acid repeat polymorphism in asporin inhibits chondrogenesis and increases susceptibility to osteoarthritis (2005)
    [s.l.] : Nature Publishing Group
    Nature genetics 37 (2005), S. 138-144 
    Details
    ISSN: 1546-1718
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Medicine
    Notes: [Auszug] Osteoarthritis is the most common form of human arthritis. We investigated the potential role of asporin, an extracellular matrix component expressed abundantly in the articular cartilage of individuals with osteoarthritis, in the pathogenesis of osteoarthritis. Here we report a significant ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/ng1496
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Ni-Fe Bimetallic Anode for Intermediate Temperature Solid Oxide Fuel Cells Using LaGaO〈sub〉3〈/sub〉 Based Oxide Electrolyte (2007)
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 539-543 (Mar. 2007), p. 1350-1355 
    Details
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Effects of various additives to Ni anode on SOFC using La0.9Sr0.1Ga0.8Mg0.2O3 basedoxide were investigated in this study. Among the examined additives, it was found that theaddition of small amount of Fe is highly effective for increasing the anodic activity. When 5 wt%Fe was added to Ni anode, the anodic overpotential was as small as 34 mV at 873 K, 0.1A/cm2,which is almost half of pure Ni anode. Since the estimated activation energy for anodic reactiondecreased, addition of Fe to Ni seems to be effective for increasing the activity of Ni for anodicreaction. XRD measurement after power generating property suggests that added Fe was formedalloy with Ni. SEM observation shows the high dispersion of Ni metal was sustained by addition ofsmall amount of Fe. Consequently, this study reveals that Ni-Fe bimetal is highly active foranodic reaction of SOFCs at decreased temperature
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/02/15/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.539-543.1350.pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...