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
    Composition, residual stress, and structural properties of thin tungsten nitride films deposited by reactive magnetron sputtering (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 1380-1388 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Thin tungsten nitride (WNx) films were produced by reactive dc magnetron sputtering of tungsten in an Ar–N2 gas mixture. The effects of the variation of nitrogen partial pressure on the composition, residual stress, and structural properties of these films as well as the influence of postdeposition annealing have been studied. The films were analyzed in situ by a cantilever beam technique, and ex situ by x-ray photoelectron spectroscopy, electron energy-loss spectroscopy, x-ray diffraction, and transmission electron microscopy (TEM). It was found that at N concentrations below 8 at. %, the films (typical 150 nm in thickness) were essentially bcc α-W. An amorphous phase was observed in the range of about 12–28 at. % N. When N concentrations reached ∼32 at. % or above, a single-phase structure of W2N was formed. Annealing of the as-deposited films resulted in crystallization of the amorphous or an improved crystallinity of the W2N structure, which was related to the N concentration. Stresses of all W and WNx films were compressive. As the N concentration was increased, the stress decreased and reached its lowest value for amorphous samples near 20 at. % N. Past this point, the compression of films rose again. These results can be ascribed to structural changes induced by the pressure-dependent variation in the average energy of particles bombarding the film during deposition. Cross-sectional TEM studies showed that all crystalline WNx films had columnar microstructures. The average column width near stoichiometry of W2N was ∼20±5 nm near the film surface. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.373827
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Residual stress, microstructure, and structure of tungsten thin films deposited by magnetron sputtering (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 177-187 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The residual stress and structural properties of tungsten thin films prepared by magnetron sputtering as a function of sputtering-gas pressure are reported. The films were analyzed in situ by a cantilever beam technique, and ex situ by x-ray diffraction, cross-sectional transmission electron microscopy (TEM), x-ray photoelectron spectroscopy, electron energy-loss spectrometry, and energy-filtered electron diffraction. It is found that the residual stress, microstructure, and surface morphology are clearly correlated. The film stresses, determined in real time during the film formation, depend strongly on the argon pressure and change from highly compressive to highly tensile in a relatively narrow pressure range of 12–26 mTorr. For pressures exceeding ∼60 mTorr, the stress in the film is nearly zero. It is also found that the nonequilibrium A15 W structure is responsible for the observed tensile stress, whereas the stable bcc W or a mixture of bcc W and A15 W are in compression. Cross-sectional TEM evidence indicates that the compressively stressed films contain a dense microstructure without any columns, while the films having tensile stress have a very columnar microstructure. High sputtering-gas pressure conditions yield dendritic-like film growth, resulting in complete relaxation of the residual tensile stresses. Structural details of the A15 W and amorphous W phases were also investigated at the atomic level using energy-filtered electron diffraction with reduced radial distribution function G(r) analysis. By comparing the experimental and simulated G(r) distributions, the A15 W structure is determined to be composed of ordered and stacking faulted W3W structures and the amorphous W has a disordered structure of W3O. The effect of oxygen in stabilizing the A15 phase found is explained on the basis of structural and thermodynamic stability. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371841
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Oxygen-induced amorphous structure of tungsten thin films (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 75 (1999), S. 2211-2213 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A combination of energy-filtered electron diffraction, electron energy-loss spectroscopy, transmission electron microscopy, and x-ray diffraction are used to establish that oxygen impurities incorporated in tungsten films prepared by magnetron sputtering in the early stage of the deposition play a dominant role in the formation of an amorphous phase. Energy-filtered electron diffraction data collected from a range of amorphous films were Fourier transformed to a reduced density function (RDF) and matched with an amorphous model. The results show that better agreement with the experimental RDF is achieved if the amorphous model consists of a random continuous matrix of clusters with W3O-like symmetry. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.124967
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Functionally Graded Materials Under Severe Thermal Environments (2005)
    Oxford, UK : Blackwell Science Inc
    Journal of the American Ceramic Society 88 (2005), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Thermal shock strengths of a plate of a functionally graded material (FGM) are analyzed when the plate is suddenly exposed to an environmental medium of different temperature. A finite element/mode superposition method is proposed to solve the time-dependent temperature field. The admissible temperature jump that the material can sustain is studied using the stress-based and fracture mechanics-based criteria. The critical parameters governing the level of the transient thermal stress in the medium are identified. The strength of FGMs under transient thermal stresses is analyzed using both maximum local tensile stress and maximum stress intensity factor criteria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1551-2916.2005.00126.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    In situ investigation of small fatigue crack growth in poly-crystal and single-crystal aluminium alloys (2002)
    Oxford, UK : Blackwell Science, Ltd
    Fatigue & fracture of engineering materials & structures 25 (2002), S. 0 
    Details
    ISSN: 1460-2695
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract  In situ scanning electron microscope observations of short crack growth in both a poly-crystal and a single-crystal alloy revealed that fatigue cracks may grow in a shear decohesion mode over a length that is several times the grain size, far beyond the conventional stage I regime. In the poly-crystal aluminium alloy 2024-T351, fatigue cracks were found to continue to grow along one shear band even after two mutually perpendicular shear bands had formed at the crack tip. For the single-crystal alloy specimen with the loading axis being nearly perpendicular to its main shear plane, mode I fatigue cracks were found to grow along the shear band. These two types of fatigue crack growth pose a significant challenge to the existing fatigue crack growth correlating parameters that are based on crack-tip opening displacement. In particular, it has been found that the cyclic crack-tip opening displacement, which accounts for both large-scale yielding and the lack of plasticity-induced crack closure, is unable to unify the growth rates of short and long cracks in aluminium 2024-T351, suggesting a possible dependence of crack growth threshold on crack length.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.8756-758x.2001.00484.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The effects of salt-loading and dehydration on atrial natriuretic peptide (ANP) gene expression
    Amsterdam : Elsevier
    Comparative Biochemistry and Physiology -- Part B: Biochemistry and 97 (1990), S. 205-208 
    Details
    ISSN: 0305-0491
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0305-0491(90)90203-6
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The decline of atrial natriuretic peptide (ANP) gene expression in older rats and the effects of ginsenoside on ANP gene expression
    Amsterdam : Elsevier
    Comparative Biochemistry and Physiology -- Part B: Biochemistry and 101 (1992), S. 35-39 
    Details
    ISSN: 0305-0491
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0305-0491(92)90155-K
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Hydrostatic stress and crack opening displacement in three-point bend specimens with shallow cracks
    Amsterdam : Elsevier
    Journal of the Mechanics and Physics of Solids 34 (1986), S. 499-510 
    Details
    ISSN: 0022-5096
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0022-5096(86)90014-1
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Crack growth resistance curves in strain-softening materials
    Amsterdam : Elsevier
    Journal of the Mechanics and Physics of Solids 34 (1986), S. 593-607 
    Details
    ISSN: 0022-5096
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0022-5096(86)90039-6
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    ON THE EQUIVALENCE OF STRESS INTENSITY AND ENERGY APPROACHES IN BRIDGING ANALYSIS (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Fatigue & fracture of engineering materials & structures 17 (1994), S. 0 
    Details
    ISSN: 1460-2695
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract— Through-thickness reinforcement is effective in suppressing delamination in composite laminates. It provides bridging in the crack wake during delamination crack growth. The closure traction behind the crack tip due to this bridging increases the delamination toughness significantly. The effect of bridging may be analysed using the stress intensity approach or the Griffith energetic approach. In this paper, delamination crack growth resistance KR,(Δa) of a double-cantilever-beam specimen, with through-thickness reinforcement, under Mode I delamination is determined using these two approaches. Additionally, the J-integral analysis is also employed. A comparison between the theoretical results predicted by these three methods is provided using the example of stitched CFRP.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1460-2695.1994.tb00234.x
    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...