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
Filter
  • American Institute of Physics (AIP)  (66)
  • Springer  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Thermal boundary resistance and diffusivity measurements on thin YBa2Cu3O7−x films with MgO and SrTiO3 substrates using the transient grating method (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 850-857 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Interface selective transient grating experiments are performed on oriented thin films (∼100 nm) of YBa2Cu3O7−x, with MgO and SrTiO3 substrates. The anisotropic YBa2Cu3O7−x thermal diffusivity constants and the thermal boundary resistance between the thin film and substrate are measured. Four different excitation and probe geometries are utilized such that each geometry results in a unique temporal decay. The grating has a significant amplitude on both sides of the film–substrate interface with a grating wave vector parallel to the interface. The four experimental geometries comprise an over-determined system that can be used to confirm the validity of the model assumptions. Numerical fits to the experimental data, using a straightforward diffusive model, are performed to obtain information on thermal diffusivity and to demonstrate the applicability of the technique to monitor anisotropic thermal relaxation processes in thin film–substrate structures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.353296
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The grating decomposition method: A new approach for understanding polarization-selective transient grating experiments. II. Applications (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 97 (1992), S. 78-85 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We apply the theory developed in Paper I to two transient grating problems that present difficulties in interpretation and/or calculation. The first application is general, and illustrates the ability of the grating decomposition method (GDM) to facilitate calculations and to provide intuition and insight in complex orientational grating experiments: we apply the GDM to nuclear optical Kerr effect (OKE) polarization gratings. We show that the circularly polarized component gratings of the polarization-grating decomposition do not contribute to the signal, and that the OKE polarization grating can therefore be viewed as the sum of two gratings with orthogonal net molecular alignments. We also use the GDM and this system to explain why polarization gratings can rotate the polarization of the probe beam. The second example is a detailed application of the GDM to an experiment in which the data cannot be fully interpreted using standard diagrammatic perturbation methods: picosecond transient gratings on the D lines of gas-phase sodium atoms. We use the GDM and effective two-interaction matrix elements to greatly simplify this problem. We show why, in atmospheric-pressure experiments, Na intensity-grating decays are dominated by excited-state quenching, whereas Na polarization-grating decays are not. We show that the polarization-grating decays are dominated by Na diffusion and are influenced by scattering among the ground-state magnetic sublevels, but are unaffected by excited-state decay. We further show why the envelopes of polarization decays do not match the corresponding intensity-grating decays at large fringe spacings in low-pressure Na cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.463525
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Picosecond polarization-selective transient grating experiments in sodium-seeded flames (1991)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 95 (1991), S. 5775-5784 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Polarization-selective transient grating experiments have been used to study the subnanosecond time scale dynamics of several sodium-seeded, premixed flames. Intensity gratings (in which both excitation beams are of the same polarization) were used to determine excited-state quenching collision rates, while polarization gratings (in which the excitation beams are cross polarized) were used to measure Na diffusion constants and the rates of Na ground state magnetic sublevel population scattering collisions. In addition, the rates of scattering between the 3P1/2 and 3P3/2 excited state levels were measured using an excited state probing scheme.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.461599
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Electronic excitation transfer in clustered chromophore systems: Calculation of time-resolved observables for intercluster transfer (1991)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 94 (1991), S. 5622-5630 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A theoretical description is given for electronic excitation transport among interacting clusters of chromophores. Each cluster is a finite volume system with a limited number of chromophores. At high cluster concentration, intercluster transfer will become significant. The theory is based on a first-order cumulant approximation of the solution to the transport master equation. Gs(t) the probability of finding the excitation on the initially excited chromophore is calculated. The problem is first solved for two clusters at fixed separations. This result is extended to many clusters and then to the thermodynamic limit of an infinite number of clusters in an infinite volume. An example calculation is performed of excitation transport among chromophores on the surfaces of interacting micelles. For realistic parameters characterizing the system octadecylrhodamine B (chromophores) in Triton X-100 micelles, it is found that intermicelle excitation transfer can compete with intramicelle transfer. For an isolated micelle–chromophore system (chromophores on the surface of a sphere), a new time domain expression for Gs(t) is obtained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.460498
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Solvent relaxation and electron back transfer following photoinduced electron transfer in an ensemble of randomly distributed donors and acceptors (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 93 (1990), S. 3550-3561 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The role of solvent relaxation in electron back transfer following electron transfer from an optically excited donor to randomly distributed acceptors is treated theoretically. The solvent dynamics are included by using a time dependent electron back transfer rate function, Keff(R,t). The solvent relaxation is parameterized by τr, the relaxation time, D, the solvent energy diffusion constant, and Δq, the potential barrier height difference between the nonequilibrium solvent state formed upon ion creation and the relaxed solvent state. The expression for the ensemble averaged donor cation state population probability, 〈Pct(t)〉, as a function of these solvent relaxation parameters is derived. Numerical calculations are presented. Relationships among 〈Pct(t)〉, the intermolecular interaction parameters, and solvent relaxation parameters provide detailed insights into the distance and time dependence of the flow of electron probability in an ensemble of donors and acceptors. The theoretical expressions can be used to calculate experimental observables such as the transient grating signal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.458787
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Reply to the Comment on: "Anisotropic reorientational relaxation in biphenyl: Transient grating optical Kerr effect measurements'' (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 93 (1990), S. 2162-2163 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.459047
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Anisotropic reorientational relaxation of biphenyl: Transient grating optical Kerr effect measurements (1989)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 6893-6902 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Subpicosecond transient grating optical Kerr effect measurements have been used to evaluate the reorientation of biphenyl molecules in neat biphenyl and n-heptane solutions. Besides an ultrafast (100 fs time scale) component associated with librational damping/dephasing, two reorientational relaxation components are observed. The slow reorientation is due to rotation around the short axes of the molecule (tumbling motion), the fast reorientation is associated with internal rotation around the central C–C bond and/or rotation of the whole molecule around its long axis (spinning motion). Whereas the tumbling motion has been observed in earlier depolarized light scattering data, the time resolved Kerr data presented here are the first ones to reveal the dynamics of the fast reorientation component and the ultrafast librational dynamics. It is shown that the diffusive reorientational relaxation must be coupled to the ultrafast librational dynamics, and implications of this coupling are pointed out.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.456264
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Theory of the phonon perturbed photon echo experiment: Direct determination of electronic excitation–phonon coupling (1988)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 88 (1988), S. 3407-3416 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A theory is presented describing the proposed phonon perturbed photon echo experiment. This experiment is a combination of picosecond time scale stimulated Raman pumping and photon echo experiments. The theory demonstrates that the phonon perturbed photon echo can directly measure electronic excitation–phonon coupling matrix elements by observing the influence of a well defined coherent phonon wave on the photon echo signal. The theory predicts that the echo pulse area (integrated intensity) is reduced. The size of this change is related to the strength of the excitation phonon coupling. In addition, a realistic estimate is made of the size of the effect, and it is shown that the experiment is feasible with available laser equipment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.453889
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Reorientational motion of a cross-link junction in a poly(dimethylsiloxane) network measured by time-resolved fluorescence depolarization (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 96 (1992), S. 3269-3278 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The reorientational dynamics of a cross-link junction in poly(dimethylsiloxane) networks, measured by the fluorescence anisotropy decay of a chromophore tagged to the cross-link, have been investigated over a range of temperatures from Tg+75 to Tg+150. The probe chromophore, 1-dimethylamino-5-sulfonylnaphthalene amide (dansyl amide), is pendant to a trifunctional silane that acts as a cross-linking molecule. In cyclohexanol, the fluorescence anisotropy decay is in agreement with Debye–Stokes–Einstein hydrodynamic theory (rotational diffusion) demonstrating that the cross-linker can be used as a probe of orientational relaxation. The fluorescence anisotropy decays at a rapid rate in an end-linked poly(dimethyl siloxane) network reflecting fast reorientational motion of the cross-link junction. This reorientation appears diffusive and has a temperature dependence in accord with the Williams–Landel–Ferry equation. A model is proposed that suggests that reorientation and translational motion of the cross-link occur simultaneously and are both coupled to fluctuations of the polymer chain ends.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.461972
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The influence of diffusion on photoinduced electron transfer and geminate recombination (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 96 (1992), S. 7410-7422 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The influence of diffusion on photoinduced electron transfer and geminate recombination in solutions of randomly distributed donors and acceptors is explored. The focus is on the effect diffusional motion has on geminate recombination. The reactive state (state following photoinduced electron transfer) probability is calculated as a function of diffusion constant and relative permittivity for three intermolecular potential cases: attractive, repulsive, and no Coulomb potentials. Also calculated are the reactive state yield and reactive state survival fraction. Both forward and back electron-transfer rates are distance dependent (not contact transfer). Any diffusion constant can be investigated, and donor–acceptor and acceptor–acceptor excluded volumes are taken into account. The model developed here is compared with slow and fast diffusion limits as well as with the theories of Smoluchowski, and Collins and Kimball.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.462391
    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...