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
    Investigation of the oxidation kinetics of NiSi2 on (111)Si by transmission electron microscopy (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 1001-1007 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A transmission electron microscopy study of oxidation kinetics of NiSi2 for both dry and wet oxidation has been carried out. Care was taken to determine the activation energies of oxidation in the temperature and time regime where the islanding of NiSi2 did not occur. For dry oxidation, activation energies for parabolic and linear growth were found to be 1.87 and 1.94 eV (with an error bar of ±0.1 eV), respectively. On the other hand, activation energies for parabolic and linear growth were found to be 1.72 and 1.59 eV (with an error bar of ±0.1 eV), respectively, for wet oxidation. The activation energy of parabolic rate constant is seen to be substantially different from those obtained previously. The difference is attributed to the occurrence and absence of islanding during oxidation in the previous and present study, correspondingly. Compared to the oxidation of TiSi2 and pure silicon, a model based on the dominant diffusing species through silicide, i.e., metal and Si for NiSi2 and TiSi2, respectively, is proposed to explain the substantial difference and closeness in linear activation energies of wet oxidation between NiSi2, TiSi2, and pure silicon, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.354945
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Investigation of the oxidation kinetics of C54-TiSi2 on (001)Si by transmission electron microscopy (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 3143-3149 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A transmission electron microscopy study of oxidation kinetics of C54-TiSi2 for both dry and wet oxidation has been carried out. Precautions were taken to determine the activation energies of oxidation in the temperature and time regime where the islanding of TiSi2 did not occur. For dry oxidation, activation energies for parabolic and linear growth were found to be 1.97 and 2.50 eV (with an error bar of ±0.1 eV), respectively. On the other hand, activation energies for parabolic and linear growth were found to be 1.88 and 2.10 eV (with an error bar of ±0.1 eV), respectively, for wet oxidation. The activation energy of parabolic rate constant is seen to be substantially different from those obtained previously. The difference is attributed to the occurrence and absence of islanding during oxidation in the previous and present study, correspondingly. The closeness of linear activation energy of TiSi2 oxidation with that of pure silicon is thought to be due to the fact that both are related to the breaking of the Si—Si bonds at the silicon surface. Orthorhombic TiO2 was observed to form on the surface of all samples wet oxidized at 880–1040 °C for 5–70 min. For dry oxidized samples, no TiO2 was detected in samples dry oxidized at 880–940 °C for 5–50 min and at 920 °C for up to 6 h. However, in samples dry oxidized at 920 °C for 10–15 h, TiO2 was found to form. For dry oxidation, it is thought that although the formation energy of TiO2 is considerably higher than that of SiO2, the nucleation barrier for forming TiO2 is higher. Only after prolonged oxidation was the nucleation barrier overcome and led to the formation of TiO2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.351476
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    A spectroscopic view of internal conversion in a small polyatomic molecule: Sub-Doppler intracavity dye laser spectroscopy of thioformaldehyde (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 97 (1992), S. 1630-1637 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Intracavity dye laser spectroscopy has been used to obtain sub-Doppler spectra of selected rotational lines in the A˜ 1A2–X˜ 1A1 410 band of thioformaldehyde with very high resolution and sensitivity. Many of the spectra show extra lines due to perturbations involving high vibrational levels of the ground state. Most of the perturbations observed for K'a = 0 and 4 are found to correlate well with previous observations of anomalously long single rotational level fluorescence lifetimes and reduced quantum yields [J. Dunlop and D. J. Clouthier, J. Chem. Phys. 93, 6371 (1990)]. S1–S0 interaction matrix elements of 0.001–0.006 cm−1 are found for levels involved in simple two level perturbations. The large number of small random perturbations by levels of the ground state is indicative of the first stages of the onset of quantum chaos in a small molecule. Some larger perturbations in the rotational structure are also observed; these are caused by additional local interactions with levels of the nearby triplet state.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.463205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Hyperfine and spin–orbit structure of the 4Δi ground state of CoO (1993)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 99 (1993), S. 6336-6344 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A detailed examination of the structure of the 4Δi ground state of gaseous CoO has been carried out from analysis of the electronic spectrum near 6300 A(ring), using intracavity dye laser and wavelength-resolved fluorescence methods. The intracavity experiments have given the details of the hyperfine structure of the two lowest spin–orbit components at sub-Doppler resolution, permitting the hyperfine parameters, a=0.02295 cm−1 and (b+c)=−0.01117 cm−1, to be derived; from the negative value of the contact interaction the electron configuration is established as (4sσ)2(3dδ)3(3dπ)2. The wavelength-resolved fluorescence experiments have given the relative positions of the four spin–orbit components of the X 4Δi state to ±0.3 cm−1. Based on these measurements, a pair of subbands sharing a common electronic upper level, but with the Ω=5/2 and 7/2 components of the ground state as lower levels, has been recognized. Rotational analysis of Doppler-limited intracavity spectra of these two subbands has given an accurate value for the Ω=5/2–7/2 separation as 304.321±0.007 cm−1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.465872
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Characterization of the Si/SiGe heterojunction diode grown by ultrahigh vacuum chemical vapor deposition (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 4921-4923 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The unipolar Si/SiGe heterojunction diode grown by ultrahigh vacuum chemical vapor deposition at 550 °C is demonstrated. The dark current density measured at 77 K is (2.5±0.1)×10−7 A/cm2 for the barrier height of 176±8 meV, at a reverse bias of 1 V. The barrier heights are measured from the activation analysis of the saturation current and compared to the theoretical values. The barrier height decreases as the thickness of the SiGe strained layer exceeds the critical thickness.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.357206
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Investigation of the oxidation kinetics of CoSi2 on (111)Si by transmission electron microscopy (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 865-870 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Transmission electron microscopy has been applied to study oxidation kinetics of CoSi2 on silicon for both dry and wet oxidation. Care was taken to determine the activation energies of oxidation in the temperature and time regime where the islanding of CoSi2 does not occur. For dry oxidation, activation energies for parabolic and linear growth were found to be 1.91 and 2.01 eV (±0.1 eV), respectively. For wet oxidation, activation energies for parabolic and linear growth were found to be 1.75 and 1.68 eV (±0.1 eV), respectively. The activation energy of the parabolic rate constant is substantially different from those obtained previously. The difference is attributed to the occurrence of islanding during oxidation in the previous study. A comparison of oxidation kinetics of CoSi2, NiSi2, TiSi2 on silicon with pure silicon substrates indicated that the oxidation kinetics are practically the same for CoSi2 and NiSi2 in the parabolic growth regime, but substantially different from those of TiSi2 on silicon and pure silicon. The similarity in oxidation kinetics of cubic CaF2 structure CoSi2 and NiSi2 on silicon with small mismatches to silicon is correlated to essentially the same stress level in these two silicides during the oxidation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.358462
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Study of photoresponse of high-Tc Y-Ba-Cu-O superconducting ultrathin films using a picosecond laser pulse train (1993)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 63 (1993), S. 2830-2832 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have systematically studied the photoresponse of Y-Ba-Cu-O (YBCO) ultrathin films to a train of picosecond laser pulses. The onset and decay of nonequilibrium superconductivity due to different levels of optical excitation can be observed within the single pulse train. Thermal and nonthermal responses can be clearly identified. In addition, the superconducting film resistance was found to increase progressively with laser power above the onset threshold. The YBCO thin films were possibly excited into a nonequilibrium intermediate (resistive) state from the superconducting state. The laser intensity dependence indicated a nonthermal origin for these voltage pulses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.110301
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Generation and measurement of picosecond voltage pulses in YBa2Cu3O7 thin films (1992)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 61 (1992), S. 489-491 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: An autocorrelation method was proposed and applied to measure the temporal decay of ultrafast voltage pulses in the superconducting state. Using a 40 ps laser, voltage pulses with fast components 〈40 ps were obtained in a YBCO thin film which was biased within the superconducting state.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.107866
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Sub-Doppler spectroscopy of thioformaldehyde: Excited state perturbations and evidence for rotation-induced vibrational mixing in the ground state (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 101 (1994), S. 7300-7310 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: High-resolution intracavity dye laser spectroscopy has been used to obtain sub-Doppler spectra of transitions to 350 rotational levels in the 410 band of the A˜ 1A2–X˜ 1A1 electronic transition of thioformaldehyde. Ground state combination differences from the sub-Doppler spectra, combined with microwave and infrared data, have been used to improve the ground state rotational and centrifugal distortion constants of H2CS. The upper state shows a remarkable number of perturbations. The largest of these are caused by nearby triplet levels, with matrix elements of 0.05–0.15 cm−1. A particularly clear singlet–triplet avoided crossing in Ka' = 7 has been shown to be caused by interaction with the F1 component of the 3162 vibrational level of the a˜ 3A2 state. At least 53% of the S1 levels show evidence of very small perturbations by high rovibronic levels of the ground state. The number of such perturbations is small at low J, but increases rapidly beyond J=5 such that 40%–80% of the observed S1 levels of any given J are perturbed by ground state levels. Model calculations show that the density and J dependence of the number of perturbed levels can be explained if there is extensive rotation-induced mixing of the vibrational levels in the ground state.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.468287
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Laser spectroscopy of the low-lying electronic states of NbN: Electron spin and hyperfine effects in the states from the configurations σδ and δπ (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 100 (1994), S. 4138-4155 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Rotational and hyperfine analyses have been carried out for the (0,0) bands of the C 3Π–X 3Δ, e 1Π–X 3Δ, and f 1Φ–a 1Δ transitions of gaseous NbN from laser excitation spectra taken at sub-Doppler resolution. The δπ C 3Π and e 1Π states lie only 102 cm−1 apart in zero order but the spin–orbit matrix element between them, which is the sum of the spin–orbit constants for the δ and π electrons, is 698 cm−1; as a result the 3Π1 spin component lies below both the 3Π0 and 3Π2 components, and its hyperfine structure is highly irregular. This irregularity is an extreme example of how cross terms between the spin–orbit interaction and the Fermi contact hyperfine operator alter the apparent value of the hyperfine a constant, the coefficient of I⋅L in the magnetic hyperfine Hamiltonian. Molecular parameters for the C 3Π and e 1Π states have been obtained from a combined fit to the two of them. Including data for the B 3Φ state recorded earlier [Azuma et al., J. Chem. Phys. 91, 1 (1989)], detailed information is now available for all six of the electronic states from the electron configurations σδ and δπ. It has been verified that the spin–orbit/Fermi contact cross terms cause roughly equal and opposite shifts in the hyperfine a constants for the singlet states and the Σ=0 components of the triplet states. After allowing for this effect, it has been possible to interpret the hyperfine a constants in terms of one-electron parameters for the δ and π electrons, in similar fashion to spin–orbit parameters. Wavelength resolved fluorescence, following selective laser excitation of the C 3Π, e 1Π, and f 1Φ states, has led to the discovery of three new electronic states, δ2 c 1Γ, δ2 A 3Σ−, and σ2 b 1Σ+, besides giving the absolute position of a 1Δ. Strong configuration interaction mixing is found to occur between the σ2 b 1Σ+ and δ2 d 1Σ+ states. The low-lying electronic states of NbN are now well understood.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.466298
    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...