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
    Optical transitions in (ZnCo)Se and (ZnFe)Se: Role of an effective p–d exchange (invited) : 38th Annual Confrerence on Magnetism and Magnetic Materials (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 5719-5724 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: In this paper we discuss photoluminescence (PL) and Raman excitations in the diluted magnetic semiconductors Zn1−xCoxSe and Zn1−xFexSe. The PL spectra associated with isolated crystal field d levels are found to rapidly weaken and/or broaden as the transition metal ion concentration approaches and increases beyond a critical value. In addition a Raman continuum, that overlaps with the optical phonon, is observed to develop when the PL features are modified. In the corresponding Zn1−xCoxSe samples the optical phonons acquire a characteristic Fano line shape suggestive of its coupling to the Raman continuum. It is proposed that these changes to the optical transitions arise from the enhancement of an effective p–d hybridization between low-lying d levels and band electrons with increasing x—an effect largely due to the proximity of the Co2+ and Fe2+ crystal field ground levels to the valence band maximum.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.355594
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Neutron scattering investigation of the ordered state of the nuclear spins in Cu at 60 nK (1990)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 67 (1990), S. 5433-5435 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We have studied the magnetic structure of the nuclear spin system in Cu below 60 nK by means of neutron scattering. The observation of the nuclear (100) superlattice reflection proves the theoretically predicted antiferromagnetic arrangement of the nuclear spins. The critical field at the lowest temperatures was 0.24 mT. Around 0.1 mT the (100) reflection could not be observed. This is taken as an indication for, possibly, a reorientation phase transitition at this field. Therefore, the phase diagram contains at least two phases. For 0.1 mT〈B〈0.24 mT strong time dependencies of the ordering were observed. At low fields (B〈0.1 mT) nucleation times of the order of 10 s have been observed. These results are discussed with respect to the cooling technique: Adiabatic demagnetization requires constant entropy, a rather unusual way to bring a system from the paramagnetic to the ordered phase.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.344580
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Fast thermoremanent magnetization in the insulating spin glass CsNiFeF6 : 37th Annual conference on magnetism and magnetic materials (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 5466-5467 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: With a newly built superconducting quantum interference device magnetometer, the time range of measurements of the thermoremanent magnetization (TRM) was extended to less than 10 ms. This new method allows a direct investigation of aging and relaxation in the spin glass region for short times. As a first example for fast TRM, the magnetization in a single crystal of the insulating spin glass CsNiFeF6 was measured in the time range −2〈log(t/s)〈3 at magnetic fields between 2 and 20 G at temperatures between 4.7 and 1.7 K. Additionally, the zero field and field cooled magnetization of this sample to temperatures up to 9 K was studied.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.353667
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Neutron scattering studies of the spin dynamics in nonlinear and Haldane systems (invited) (1990)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 67 (1990), S. 5593-5598 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: In 1D magnets contributions to the spin dynamics which are outside the scope of spin-wave theory can be studied theoretically as well as experimentally. Two prominent examples of such effects are discussed here: solitons and the Haldane gap. We discuss inelastic polarized neutron scattering results on the stability of solitons in CsNiF3 and on the existence of the Haldane gap in CsNiCl3. In both cases, the separate determination of the different correlation functions 〈SαSα〉 with α=x,y,z is essential for definite conclusions: Solitons in CsNiF3 appear to be much more stable than expected from classical theories, and the Haldane gap is the only explanation for the observed gaps in CsNiCl3.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.345895
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Optical properties of the layered transition-metal-dichalcogenide ReS2: Anisotropy in the van der Waals plane (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 5266-5268 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The spectral quantum efficiency in ReS2 heterodiodes was measured in the wavelength region between 600 and 850 nm. Anisotropy effects in the van der Waals plane were observed by means of linearly polarized light at normal incidence to the (001) plane of ReS2 single crystals. The anisotropy in quantum efficiency reaches its maximum at λ=627 nm and therefore, ReS2 devices are well suited for detecting the angle of polarization in experiments using a HeNe laser. At wavelengths above 750 nm the sign in polarization quantum efficiency changes due to various optical transitions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.354268
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    X-Ray Diffractometer for High Pressure and Low Temperatures (1991)
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 79-82 (Jan. 1991), p. 419-426 
    Details
    ISSN: 1662-9752
    Quelle: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/02/21/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.79-82.419.pdf
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Photo-induced tunneling spectroscopy of ReS2: Dramatic increase of the quantum efficiency by chemical treatment (1993)
    Springer
    Applied physics 57 (1993), S. 221-223 
    Details
    ISSN: 1432-0630
    Schlagwort(e): 68.65 ; 79.60
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau , Physik
    Notizen: Abstract In this work we present a systematic study of the local photovoltaic properties of ReS2, using a scanning tunneling microscope (STM). The tunneling junction of the STM was optically illuminated during the tunneling process. The phase sensitive detected photo-induced tunneling current (PITC) was studied as a function of wavelength and surface topography. In order to improve the performance of ReS2 solar cells, the samples were treated with NaI/I2 and EDTA solutions. Relative to the untreated sample, the EDTA-treated samples show an increase in the photo-induced tunneling current by a factor of 8–10 in the whole spectral range, the NaI/I-treated samples by 2–3. Two dimensional mapping of the PITC was performed on an atomic scale and compared to the surface topography.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00332592
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Influence of growth conditions on the structural, optical, and electrical properties of ZnSe films (1992)
    Springer
    Applied physics 54 (1992), S. 455-459 
    Details
    ISSN: 1432-0630
    Schlagwort(e): 61.10.-i ; 78.55.-m ; 72.80.Ey
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau , Physik
    Notizen: Abstract ZnSe films were grown by chemical vapour deposition on GaAs substrates. The influence of the source temperature (between 820 and 900° C) and the substrate temperature (between 620 and 790° C) on the film properties were investigated by Hall measurements, X-ray diffraction, and photoluminescence. With respect to blue luminescent devices the ratio of excitonic to deep level transitions was found to be optimum at low growth rates when the source temperatures were kept below 840° C. P-type conduction up to a net carrier concentration of 8×1018 cm−3 could be obtained by substrate temperatures above 700° C. Lattice contraction versus substrate temperature pointed to a reduced incorporation of donors at higher growth temperatures.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00324171
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Reflection-scanning near-field optical microscopy and spectroscopy of opaque samples (1994)
    Springer
    Applied physics 59 (1994), S. 103-108 
    Details
    ISSN: 1432-0630
    Schlagwort(e): 07.60.Pb ; 07.65.Eh ; 78.65-s
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau , Physik
    Notizen: Abstract Opaque samples are imaged by Scanning Nearfield Optical Microscopy (SNOM) in reflection mode: A quartz glass fiber tip is used both to illuminate the sample and to collect light locally reflected from or emitted by the surface. The collected light is coupled out by a 2×2 fiber coupler and fed into a grating spectrometer for spectral analysis at each sampled point. The tip-sample distance is controlled by a shear-force feedback system. The simultaneous measurement of topography and optical signals allows an assessment of imaging artifacts, notably topography-induced intensity changes. It is demonstrated that an optical reflectance contrast not induced by topographic interference can be found on suitable samples. Local spectral analysis is shown in images of a photoluminescent layer.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00332201
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Arabin-Pessar — Ein Ersatz der Cerclage (1993)
    Springer
    Archives of gynecology and obstetrics 254 (1993), S. 1277-1282 
    Details
    ISSN: 1432-0711
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Zusammenfassung Von 1986 – 1989 wurde unter Studienbedingungen anstelle der operativen Cerclage bei 85 Schwangeren aus prophylaktischer und bei 82 Patientinnen aus therapeutischer Indikation das Cerclage-Pessar eingesetzt. Bei 7 Patientinnen wurde bei Verzicht auf eine Notfall-Cerclage dieses Vorgehen gewählt. Sowohl diese Ergebnisse wie auch die seitherige breite Anwendung dieser Methode bei Modifikation des Pessars als Ersatz zur operativen Cerclage belegen die hohe Effektivität des Cerclage-Pessars durch feste Umschnürung und Rekonfiguration der Zervix und seine daraus resultierende Stützfunktion. Bis auf einen verstärkt auftretenden Fluor albus zeigten sich keine Nebenwirkungen. Infektiöse Komplikationen traten nicht auf. Bei 89% der Schwangeren konnte das Pessar nach komplikationslosem Schwangerschaftsverlauf nach Vollendung der 36. SSW entfernt werden. Das Cerclage-Pessar stellt sowohl aufgrund seiner einfachen Anwendung und fehlenden ernsthaften Nebenwirkungen wie auch unter Kosten-Nutzen-Aspekten eine vorteilhafte Alternative zur operativen prophylaktischen und therapeutischen Cerclage dar. Eine Operation kann ausgewählten Fällen vorbehalten bleiben. Unter Beachtung der entsprechenden Kontraindikationen ist dem Cerclage-Pessar der Vorzug zu geben.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02266394
    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...