Library

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
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 1446-1453 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Amorphic diamond films can be grown in an ultrahigh vacuum environment free from hydrogen with a laser plasma discharge source. This technique produces films that adhere more readily to materials for which there are important applications as protective coatings. In this work adhesion and mechanical properties of amorphic diamond films have been examined. A beam bending method has been used to measure the internal stress and a relatively low value of compressive stress was found. The dependence of stress on the laser intensities at the graphite ablation target has been studied. Analyses of these films on silicon, SiO2, ZnS, and TiAl6V4 by Rutherford backscattering spectrometry show significant interfacial layers with compositions of SiC, C0.5SiO2, C2.5ZnS, and C0.62Ti0.35Al0.05V0.02, respectively. Adhesion properties on ZnS and other substrates have also been examined for harsh environments. The mechanical properties of hardness, Young's modulus, and stiffness have been obtained with a nanoindentation technique. These results together with the minimal amount of hydrogen in our process, make amorphic diamond an excellent candidate for direct deposition on several substrates including ZnS.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 239-245 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Recent experiments have identified the microstructure of amorphic diamond with a model of packed nodules of amorphous diamond expected theoretically. However, this success has left in doubt the relationship of amorphic diamond to other noncrystalline forms of carbon. This work reports the comparative examinations of the microstructures of samples of amorphic diamond, i-C, and amorphous carbon. Four distinct morphologies were found that correlated closely with the energy densities used in preparing the different materials.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 3260-3265 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Films of amorphic diamond can be deposited from laser plasma ions without the use of catalysts such as hydrogen or fluorine. Prepared without columnar patterns of growth, the layers of this material have been reported to have "bulk'' values of mechanical properties that have suggested their usage as protective coatings for metals. Described here is a study of the bonding and properties realized in one such example, the deposition of amorphic diamond on titanium. Measurements with Rutherford backscattering spectrometry and transmission electron microscopy showed that the diamond coatings deposited from laser plasmas were chemically bonded to Ti substrates in 100–200-A(ring)-thick interfacial layers containing some crystalline precipitates of TiC. Resistance to wear was estimated with a modified sand blaster and in all cases the coating was worn away without any rupture or deterioration of the bonding layer. Such wear was greatly reduced and lifetimes of the coated samples were increased by a factor of better than 300 with only 2.7 μm of amorphic diamond.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 7862-7870 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: It has been previously reported that layers of amorphic diamond can be grown in a UHV environment free from hydrogen with a laser plasma source. Some advantages are offered by this technique which produces films that adhere more readily to materials for which there are important applications. Theory has recently suggested a structure for amorphic diamond that comprises nodules of carbon atoms linked by sp3 bonds in a matrix of other polytypes and the purpose of this article is to communicate strong evidence in support of that hypothesis. Extensive examinations of a variety of films with a scanning tunneling microscope show a clearly prevalent structure composed of dense nodules. Grain size is about 1000 A(ring) and the diamond character is attested by the agreement of morphology, high density, optical properties, soft x-ray spectroscopy, hardness, and lack of appreciable hydrogen. Measurements agree in supporting a fraction of about 75% diamond contents. The principal conclusion is that this material prepared with a laser plasma source has the structure expected for amorphic diamond.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 88 (1988), S. 3061-3071 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: This work reports the measurements of rate coefficients for excitation transfer reactions of metastable He(2 3S) atoms, produced in 0.3–4 atm of helium, with various reactants presenting a wide range of characteristics. In all cases studied, three-body reaction channels were identified with most probable values of rate coefficients lying in the range from 0.2 to 6.7×10−31 cm6 s−1, for Ne and N2O, respectively. These are generally more than one order of magnitude smaller than previously reported. The interpretation of this discrepancy in terms of a more reactive intermediate He2(Σ*) complex in dynamic equilibrium with the He(2 3S) population seems to be confirmed, and is analyzed in some detail.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 64 (1993), S. 2570-2573 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A detection system for conversion electron Mössbauer spectroscopy is described. A chevron microchannel plate assembly attached to a two-stage electrostatic lens is used to preferentially detect electrons with energies ≤15 eV. Mössbauer spectra collected with these electrons can provide information about a variety of solid-state surface phenomena.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A method of obtaining absolute, direct measurements of the spatial and spectral characteristics of bremsstrahlung is discussed. This technique, called x-ray activation of nuclei (XAN) is based on the use of well-known photonuclear reactions which populate long-lived nuclear isomers. These populations sample incident photon continua at discrete excitation energies and effectively store this information for convenient retrieval following the irradiation of gram-sized targets. Recently a series of experiments has been conducted which has significantly expanded the available data for the photoexcitation of a wide range of isomers at higher energies. Thus it has become feasible to extend the use of XAN to energies approaching 4 MeV. The utility of this technique is demonstrated by the characterization of bremsstrahlung from the newly installed research linac at the University of Texas at Dallas.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 64 (1993), S. 2320-2325 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: X-ray diodes driven by repetitively pulsed Blumleins have been shown to be able to deliver high dose rates of x rays in pulses of nanosecond duration. Reported here is a study of the scaling of such devices conducted to isolate the primary factors limiting performance. Low residual gas pressure in the output diode together with the critical alignment of the electrodes were found essential for enhanced output. Optimizations served to increase the x-ray yield by an order of magnitude and the resulting performance is reported. At the output window, dose rates exceeding 1.4 kR min−1 were obtained in nanosecond pulses from the finished device of table top size at a charging voltage of 30 kV and a pulse repetition rate of 50 Hz.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 70 (1948), S. 3008-3011 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 54 (1989), S. 216-218 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Amorphic diamond films characterized by a high percentage of sp3 bonds have been prepared in an UHV environment with a laser plasma source of carbon ions. Peak power densities in excess of 1011 W/cm2 were found necessary to produce films at growth rates of 0.5 μm/h over areas of 20 cm2 having optical quality sufficient to show bright interference colors.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...