Search Results - (Author, Cooperation:B. Ittermann)

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  1. 1
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    Publication Date:
    2014-07-22
    Publisher:
    Nature Publishing Group (NPG)
    Print ISSN:
    0028-0836
    Electronic ISSN:
    1476-4687
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Adolescent ; Alcohol Drinking/*psychology ; Alcoholism/genetics/prevention & control/*psychology ; Artificial Intelligence ; Brain/physiology ; Cognition/physiology ; Environment ; Humans ; Life Change Events ; Longitudinal Studies ; *Models, Theoretical ; Personality/physiology ; Polymorphism, Single Nucleotide ; Psychology ; Reproducibility of Results ; Risk Factors
    Published by:
    http://www.nature.com/

    Latest Papers from Table of Contents or Articles in Press
  2. 2
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    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Spin polarized 12B nuclei were produced in a 11B(d,p)12B nuclear reaction and recoil implanted into a type Ib diamond sample at doses below 1011 cm−2. β-radiation detected nuclear magnetic resonance spectra were measured directly after implantation at sample temperatures ranging from 300 to 800 K. The polarization asymmetry at the Larmor resonance yielded fractions of boron ions at sites of full tetrahedral symmetry of 12(1)% at 300 K, increasing to 17(2)% at 800 K. It is argued that these boron atoms are incorporated substitutionally by direct replacement collisions during the implantation process. The resonance spectra also showed additional boron at low-symmetry sites. © 1997 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.120472

    Articles: DFG German National Licenses
  3. 3
    Mai, F. ; Ittermann, B. ; Füllgrabe, M. ; Heemeier, M. ; Kroll, F. ; Marbach, K. ; Meier, P. ; Mell, H. ; Peters, D. ; Thieß, H. ; Ackermann, H. ; Stöckmann, H.-J.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 2001
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    12B probe nuclei are implanted in amorphous Si and monitored by β-radiation-detected nuclear magnetic resonance (β-NMR). Independently of growth conditions and impurity content, we find the same frequency distribution in a variety of samples. This is interpreted as an intrinsic signature of the amorphous environment while preferential B–H pairing is not observed. Comparing our data with earlier 11B-NMR work, we find the local B configuration to be completely controlled by the incorporation process. In our low-dose implantation experiment, all B is fourfold coordinated and electrically active. This is in contrast to gas-phase doping or high-dose implantation where the threefold coordination prevails. © 2001 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.1384482

    Articles: DFG German National Licenses
  4. 4
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    ISSN:
    0375-9601
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    http://linkinghub.elsevier.com/retrieve/pii/0375-9601(87)90759-6

    Articles: DFG German National Licenses
  5. 5
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    ISSN:
    0168-583X
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    http://linkinghub.elsevier.com/retrieve/pii/0168-583X(92)95190-3

    Articles: DFG German National Licenses
  6. 6
    Staff View
    ISSN:
    0168-583X
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    http://linkinghub.elsevier.com/retrieve/pii/0168-583X(86)90111-4

    Articles: DFG German National Licenses
  7. 7
    Staff View
    ISSN:
    0168-583X
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    http://linkinghub.elsevier.com/retrieve/pii/0168-583X(93)96107-N

    Articles: DFG German National Licenses
  8. 8
    Staff View
    ISSN:
    1434-6036
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract The spin-lattice relaxation of12B in single-crystal aluminum was measured by β NMR in the temperature range 290 to 700 K. The total relaxation rate was separated into two well understood contributions caused by the interaction with conduction electrons and by12B diffusion, and into a third unexplained part at high temperatures. From the comparison of the diffusional relaxation rate with theoretical calculations it was concluded that the nearest neighbours of12B, trapped in the octahedral interstitial site, are displaced away by 8.8 (30)%.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF01323732

    Articles: DFG German National Licenses
  9. 9
    Staff View
    ISSN:
    1434-6036
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract The dipole-dipole interaction of extremely diluted probe nuclei with their surrounding host nuclei gives rise to mutual flip-flop processes of the nuclear spins. As energy has to be conserved in this so-called cross-relaxation (CR) process a transfer of polarization from the probes to the host nuclei occurs only at certain values of the inductionB leading to resonance-like dips in the probe's polarization. For the system12B in single-crystal aluminium CR spectra were measured forB=7...400 mT andT=310...410 K at various crystal orientations relative toB. All the spectra could be well explained by a theoretical calculation assuming the octahedral interstitial site for12B.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF01390653

    Articles: DFG German National Licenses
  10. 10
    Staff View
    ISSN:
    1434-6036
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract Polarised β emitting12B nuclei were recoil implanted into single crystalline vanadium atT=305 K. β radiation detected nuclear magnetic resonance measurements showed that two implanation sites occur simultaneously which were identified as the substitutional site and an interstitial site with axial symmetry. Extensive cross-relaxation measurements were performed on12B in both lattice positions. By this means the interstitial site could be identified as the octahedral one. The impurity induced electric field gradients at nearest and at next nearest51V neighbours about12B could be determined for both implantation sites.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF01316702

    Articles: DFG German National Licenses
  11. 11
    Staff View
    ISSN:
    1572-9540
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract The cross-relaxation technique was used to determine the implantation sites of12B in Al and Cu crystals. From the temperature dependence of the cross-relaxation spectra information on the diffusion of the probes was obtained.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF02399865

    Articles: DFG German National Licenses
  12. 12
    Staff View
    ISSN:
    1572-9540
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract Using β-NMR with12B as nuclear probes the temperature dependence of the lattice-site occupation of boron implanted into heavily doped silicon is studied. In p-type material the unperturbed substitutional fraction of12B increases from 10% at 300 K to ≃40 % at 950 K. In n-type material this fraction starting from 20% at 300 K approaches the saturation value of ≃80 % at 600 K already. This behaviour suggests that the site of implanted boron in silicon is controlled by the Fermi level.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF02399866

    Articles: DFG German National Licenses
  13. 13
    Staff View
    ISSN:
    1572-9540
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract Cross-relaxation resonances of the polarization of12B nuclei in single-crystal Vanadium were observed at various values of the external B field. From the comparison with calculated relaxation spectra the electric field gradients at the neighbouring host nuclei were determined and the locations of12B were found to be the substitutional and the octahedral interstitial sites.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF02399864

    Articles: DFG German National Licenses
  14. 14
    Staff View
    ISSN:
    1572-9540
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract An introduction to the principles of the β-NMR method is presented and its potential in the field of defect research in semiconductors is discussed. This is followed by a review of experimental applications to date and a description of several examples in some detail.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF00567582

    Articles: DFG German National Licenses
  15. 15
    Staff View
    ISSN:
    1572-9540
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract The dipole-dipole interaction between polarized β active probes implanted into a metal and the surrounding host nuclei may lead to a transfer of polarization from the probe to the host. As energy must be conserved in this cross-relaxation (CR) process, resonance-like dips show up at certainB values, if the polarization of the probes is measured as a function of magnetic inductionB. The probe isotope12B has been studied in several metallic stoppers. For12B in the fec crystals Al, Cu the three possible cubic implantation sites could easily be discriminated by means of the CR technique. The temperature dependence of the dips yielded information on the diffusion of the probes. In the case of12B, in Cu above 400 K a further CR structure was found due to trapping of the probe at another site. In the bcc metal VCR spectra belonging to two different12B trapping sites could be separately registered using a special radiofrequency technique. Both, static and dynamical properties of the CR could be quantitatively explained by theory.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF02405144

    Articles: DFG German National Licenses
  16. 16
    Staff View
    ISSN:
    1572-9540
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract Spin polarized radioactive 12B, 12N, and 8Li probe nuclei are implanted in nominally undoped ZnSe at stationary concentrations ≤ 1010 cm-3. These light dopants, one donor and two acceptors, are characterized by β-radiation detected nuclear magnetic resonance (β-NMR) measurements. The donor 12B and the acceptor 12N show quite similar and rather simple implantation behaviour, the situation is markedly different for the second acceptor 8Li, however. This contrast indicates that in semi-insulating ZnSe the structure of dilute impurities is controlled by individual, element-specific properties.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1023/A:1017033019731

    Articles: DFG German National Licenses
  17. 17
    Staff View
    ISSN:
    1572-9540
    Keywords:
    β-NMR ; ion implantation ; doping problems ; ZnSe
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract β-active probe nuclei are implanted in nominally undoped ZnSe crystals. β-radiation detected nuclear magnetic resonance (β-NMR) studies are described for two different probe nuclei, 8Li and 12B. This way, the implantation behavior of two “opposite”dopants, one acceptor (Li) and one donor (B) can be characterized by the same microscopic technique. Such characterizations are attempted in terms of the structure of intermediate or final lattice sites, defect charge states, or the kinetics of defect reactions and site changes.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1023/A:1012634505329

    Articles: DFG German National Licenses
  18. 18
    Staff View
    ISSN:
    1572-9540
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract β-radiation detected nuclear magnetic resonance (β-NMR) measurements of12B occupying sites with noncubic surroundings after implantation into Si have been extended from p-type to moderately doped n-type material. The quadrupole split signals observed in both materials indicate the existence of the same interstitial related boron defect but with lower thermal stability in n-type Si.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF00567591

    Articles: DFG German National Licenses