Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    Scaling approaches to magnetization measurements of melt-textured (Y1−xPrx)Ba2Cu3O7−δ (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 2308-2314 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Scaling approaches to magnetization measurements are explored on a set of melt-textured (Y1−xPrx)Ba2Cu3O7−& dgr; samples with different Pr concentrations. When normalized with corresponding scaling parameters Hm, Mm, and Jm, respectively, magnetic hysteresis loops and related critical current densities for different temperatures from 4.5 to 75 K are all found to exhibit scaling behavior. It is shown that for low scaled field (h) region, this behavior can be described qualitatively well based on an extended critical-state model. The effective activation energy extracted from magnetic relaxation measurements can also be qualitatively described by a scaling relation within the framework of collective-pinning theory. In addition, Pr doping is found not to influence the scaling approaches themselves up to the highest level investigated in the present work. However, the scaled magnetic hysteresis loop width, critical current density, and effective activation energy are all increased by Pr doping, further suggesting the enhancement of flux pinning for our samples. Furthermore, experimental results and fitting parameters are discussed as well with respect to relevant scaling background models. © 1997 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.364291
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Existence of a Pb1-like defect center in porous silicon (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 1759-1763 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We performed a detailed study of electron spin resonance (ESR) spectra of porous silicon (PS) samples at different stages of treatment and with different porosities. In addition to the commonly observed Pb0-like dangling bond, results of curve fitting to our ESR spectra show that a Pb1-like center, similar to the Pb1 center observed at the (100) crystalline-Si/SiO2 interface, appears in the PS nanostructure. The ratio of the number of Pb1-like centers to that of Pb0-like centers is related to the PS porosity. Remote hydrogen plasma processing of the annealed PS does not change the ratio significantly, although the total numbers of Pb0-like and Pb1-like centers are reduced and photoluminescence efficiency is improved.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.358433
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    The effects of various alloying elements on modifying the elevated temperature magnetic properties of sintered Nd-Fe-B magnets (1988)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 63 (1988), S. 3516-3518 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The effects of the alloying elements Co, Dy, Er, Al, and Nb on modifying the elevated temperature properties of sintered Nd-Fe-B–based permanent magnets have been studied in our laboratory. The results are summarized and analyzed. Small Nb additions increase coercivity and improve elevated temperature properties. Higher Nb additions lead to decomposition of the 2:14:1 phase into a 2:17 phase and a new magnetic phase with a Curie point around 350 °C. The effectiveness of Nb additions appears to be associated with the rare-earth content of the magnets.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.340727
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Development of a hard x-ray imaging microscope : Proceedings of the 5th international conference on synchrotron radiation instrumentation (1995)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 2287-2289 
    Details
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: A hard x-ray imaging microscope based on a phase zone plate has been developed and tested. The zone plate, with a 5 cm focal length and a 0.2 μm smallest linewidth, was used to image 8 keV x rays from the samples. The imaging microscope can be used to obtain nearly diffraction-limited resolution over the entire imaging field, and its resolution is almost independent of source size and source motions. We have tested such an imaging microscope, and a resolution of about 0.4 μm was obtained. The images were obtained with an exposure time of less than 1 min, for a magnification factor of 30 in the x rays. The x rays were then converted into visible light, and another 7 times magnification were obtained by using a lens system coupled to a charge coupled device camera. The results from the imaging microscope, and possible applications, will be discussed. © 1995 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1145666
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Irreversible flux losses of Nd-Fe-B magnets at elevated temperatures: Errors due to sample geometry (1988)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 64 (1988), S. 5522-5524 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Irreversible flux losses during thermal cycling or aging are commonly measured in open circuit on axially magnetized cylinders or square prisms. The reported results are usually tied to a mean operating-point permeance P derived from a dimensional ratio for the sample on the often unstated assumption that definable demagnetizing factors exist for both geometries. Experimental results on several shapes of different Nd-Fe-type magnets show that this can be misleading. Prisms always show a significantly better apparent stability than cylinders of presumably equivalent P. This means that loss data from different sources cannot be easily compared. Investigators should always precisely describe the sample shapes and coil configurations they used. Dimensional ratio rather than just P should be specified. Standardization to tests on cylinders is recommended.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.342323
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Observation of nonstatistical ortho–para ratio in hydrogen recombination at low temperatures (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 96 (1992), S. 4032-4034 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: We have demonstrated that the molecular hydrogen obtained from atomic recombination at 300 mK has nonstatistic ortho–para ratio. The ortho para conversion is less than 3% in the vibrational relaxation phase. We suggest that it is possible to carry out detailed comparison between calculations and measurements at conditions similar to our experiments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.461854
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Stability of far fields in double heterostructure and multiple quantum well InAsSb/InPAsSb/InAs midinfrared lasers (1997)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 70 (1997), S. 3236-3238 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Far fields in perpendicular direction to the junction are investigated in double heterostructure (DH) and multiple quantum well (MQW) midwave-infrared InAsSb/InPAsSb/InAs lasers (λ=3.2–3.6 μm). Strong broadening of the far fields in the DH lasers was observed with increases in temperature and/or current. On the contrary, MQW lasers with otherwise identical structure exhibit very stable far fields as narrow as 23° for all the operating conditions investigated. Our experiment and theoretical modeling suggest that these different behaviors of far fields in DH and MQW lasers are attributed to the refractive index fluctuation in the InAsSb laser active region. © 1997 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.119135
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    High power InAsSb/InPAsSb/InAs mid-infrared lasers (1997)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 71 (1997), S. 2430-2432 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We demonstrate high-power InAsSb/InPAsSb laser bars (λ(approximate)3.2 μm) consisting of three 100-μm-wide laser stripes of 700 μm cavity length, with peak output power up to 3 W at 90 K, and far-fields for the direction perpendicular to the junction as narrow as 12° full width half maximum. Spectra and far-field patterns of the laser bars are shown to have excellent characteristics for a wide range of operating conditions, suggesting the possibility of even higher light power emission with good beam quality. Joule heating is shown to be the major factor limiting higher power operation. © 1997 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.120082
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Enhancement and stabilization of porous silicon photoluminescence by oxygen incorporation with a remote-plasma treatment (1993)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 62 (1993), S. 1152-1154 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We report a treatment that enhances and stabilizes the photoluminescence (PL) from porous Si films. Films prepared by anodization in a 50% HF/ethanol solution were annealed at 450 °C in vacuum, exposed to air, and then exposed to a remote-hydrogen plasma. Infrared absorption spectroscopy revealed that the concentration of oxygen, rather than hydrogen, was increased by the processing steps, and that silicon dihydride species had been eliminated from the surface. The PL from a treated film was initially ∼30 times more intense than from the as-etched films. The PL intensity increased with illumination time in air until a steady-state intensity was reached.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.108772
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Electron spin resonance study of the dangling bond in amorphous Si and porous Si (1993)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 63 (1993), S. 1657-1659 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We compare the electron spin resonance (ESR) signal of the dangling bond in porous silicon (PS) layers, produced by electrochemical etching, to the ESR signal from hydrogenated amorphous Si(a-Si:H) films. The anisotropy of the ESR signal from PS showed g values varying as for the Pb Si/SiO2 interface dangling bond. The g value varies from g(parallel)=2.0020 to g⊥=2.0080 with an inhomogeneously broadened line width increasing from 1.8 to 3.8 G. An ESR powder line, with superhyperfine and strain broadening intrinsic to PS, has more anisotropy in g(parallel)−g⊥ and less inhomogeneous broadening than does the dangling bond line in a-Si:H. No evidence was seen for light-induced metastability on a H-passivated PS film.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.110727
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...