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
    Depth inhomogeneity of porous silicon layers (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 2990-2993 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The two possible causes of depth inhomogeneities of the microstructure of porous silicon are changes in the HF concentration with depth and a varying chemical etching rate of the porous silicon layer. During anodization chemical etching will become important for microporous silicon — e.g. p-porous silicon — due to the large internal surface area, especially at long etching times. On the other hand, a considerable decrease of the HF concentration will occur during etching with high current densities to produce p+-porous silicon with high porosities. We have investigated the depth inhomogeneity of porous silicon layers by spectroscopic ellipsometry, Raman spectroscopy and photoluminescence measurements. From a line shape analysis of the Raman signal a size distribution of nanocrystals is deduced. For p-porous silicon smaller nanocrystals are found near the surface of the layer; for p+-porous silicon etched with high current densities smaller nanocrystals are found near the porous silicon/substrate interface. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.363156
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    A Raman study of Au/Te/Au/GaAs (100) ohmic contacts (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 739-743 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Ohmic contacts produced by high-energy pulsed laser beam alloying Au/Te/Au/n-GaAs are investigated by micro Raman spectroscopy. The results are compared to those from furnace annealed ohmic contacts. For the furnace as well as for the laser annealed ohmic contacts, no evidence for a doping of the contact region is found in the Raman spectra. The presence of a highly disordered GaAs surface layer is observed for both types of contacts. In addition, after furnace processing a Ga2Te3 layer is formed. These results are consistent with earlier Mössbauer studies. For the laser alloyed samples the results strengthen the role of a defective/disordered interface structure where conduction might occur by a resonant tunneling process involving localized gap states.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.351336
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The orientation of the magnetization of thin films as determined by the Hall effect (1987)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 61 (1987), S. 3816-3818 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The Hall effect is a useful probe of the magnetization in thin metallic films since the signal is inversely proportional to the film thickness. Previously, the minimum in the coercivity, derived from the Hall hysteresis loop as a function of the angle of the applied field, has been used to determine the hard axis of magnetic thin films. A vibrating sample magnetometer can be used in this fashion if coherent rotation is the magnetization reversal mechanism. However, we show that even in the case of the Stoner–Wohlfarth model, the minimum of the Hall coercivity does not coincide with the hard axis. We propose an alternative method for determining the easy axis, which is independent of the magnetization reversal mechanism and does not require measuring the entire hysteresis loop. In addition, since for an arbitrary orientation of the applied field the measured Hall voltage will contain components due to magnetoresistance as well as the Hall effect, it is possible to extract a measure of the in-plane and perpendicular magnetization. Using this information, we derive a method of producing vector plots that show the magnitude and direction of the magnetization as a function of applied field for various applied-field orientations. Examples using CoCr and TbFe will be presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.338606
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The effect of aluminum gate thickness on charge trapping in metal-oxide-semiconductor devices (1989)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 66 (1989), S. 4821-4826 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Metal-oxide-semiconductor devices with variable aluminum gate thickness were electrically stressed by constant-current Fowler–Nordheim tunneling, until intrinsic oxide breakdown was achieved. I-V and C-V measurements were used to detect oxide-bulk trapping and interface-state generation rates during the stressing process. It was found that these rates were affected by the Al thickness only in the initial stages of the stressing, and that these rates are not a simple monotonic function of the Al gate thickness, but reach their maximum value between 500 and 1000 A(ring) of Al thickness.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.343797
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Generation and anneal of a new kind of interface state in stressed and high-temperature annealed metal-oxide-semiconductor devices (1992)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 60 (1992), S. 186-188 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Polycrystalline silicon (poly) gate metal-oxide-semiconductor (MOS) transistors were electrically stressed by constant-current tunneling. After the stress the devices were thermally annealed for variable times in the temperature range between 800 and 950 °C, and a second tunneling stress was performed. Capacitance-voltage (C-V) curve broadening and a charge pumping (CP) technique were used to detect interface state generation. It was found that the stress generated interface states are totally annealed by the thermal treatment. On the other hand, generation rates and saturation values, due to the second stress after annealing, exceed those of the fresh devices. Analysis of the generation process indicates that two types of interface states are generated: one, similar in its generation rate and saturation value to that of a fresh device, and another one, which is characterized by a higher generation rate and saturation value, is attributed to a new type of latent site. The density of this new type of latent interface states site decays exponentially with the annealing time. The annealing rate follows a temperature-dependent Arrhenius function. The anneal of this new type of interface state is characterized by an activation energy of 3.47 eV.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.106958
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Effect of high-temperature anneal on interface states generation in stressed metal-oxide-semiconductor devices (1991)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 58 (1991), S. 598-600 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Polycrystalline silicon gate metal-oxide-semiconductor transistors, fabricated with polycrystalline silicon leads, were repeatedly electrically stressed by constant-current Fowler–Nordheim tunneling cycles. After every stress cycle the devices were annealed for various time intervals at 950 °C. Capacitance-voltage measurements were used to detect stress-related interface-state generation rates and saturation values. It was found that although the stress-generated interface states are totally annealed by the thermal treatment, their generation rates and saturation values after anneal are a strong function of the anneal time, significantly exceeding the values of the fresh devices and inversely dependent on the anneal time. From the results it is concluded that a new type of latent interface-state sites is generated by the combination of tunneling stress and high-temperature annealing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.104598
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Kinematics of a rolling tire and its application to tire performance (1959)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 2 (1959), S. 174-180 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A geometrical analysis is given of the tread motions occurring in the contact length of a rolling tire. Both the case of a free rolling wheel and that of a wheel under torque are discussed. We have derived expressions and curves for the relative slip and compressions which occur at the contact length for the two conditions. It is found that two important structural features control the nature of tread motions. These are the torsional rigidity of the sidewall and the compressibility of the tread. In addition, the implication of the analysis in tire design and performance are discussed.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1959.070020507
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Characterization of a vulcanizate of the halogenated butyl rubber, MD-551. I. Gum properties (1961)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 5 (1961), S. 322-330 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: We have found that vulcanizates of MD-551 and butyl rubber at identical crosslink densities have similar properties in low deformation tests at room temperatures. At high extension, the butyl has considerably higher tensile strength which we have associated with crystallization. The MD-551, on the other hand, shows heat stability far superior to that of butyl. It is postulated here that both these differences follow from the nature of the crosslinks in each polymer. The crosslinks in the MD-551 are thought to be both mechanically and chemically more stable than those in butyl. This prevents crystallization on stretching and enhances high temperature stability. Thus far, we have been concerned only with the gum properties of the MD-551. From our previous work, we would expect carbon black to improve the tensile properties of MD-551. Furture work will therefore be concerned with properties of reinforced MD-551. In addition, studies will be made in order to learn more about the crosslinks and how they affect vulcanizate performance.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1961.070051512
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Response of elastomers to any forcing function (1960)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 4 (1960), S. 269-276 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The dynamic behavior of elastomers is usually studied in terms of a sinusoidal system. The theoretical and practical limitations of such analysis are discussed. A method which permits calculation of dynamic properties over a wide range of frequencies and forcing functions is described. The theoretical justification and limitations as well as the experimental setup are presented. Using SBR, natural rubber, and butyl, examples of the dynamic responses for various forcing functions are shown. The analogue computer is used to show properties of the above described rubbers which are useful from both the theoretical and application-oriented viewpoints.
    Additional Material: 23 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1960.070041204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Computer extended series for a thermally driven gas centrifuge (1986)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 6 (1986), S. 395-401 
    Details
    ISSN: 0271-2091
    Keywords: Computer Extended Series ; Gas Centrifuge Theory ; MACSYMA ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Linearized, multidimensional, thermally driven flow in a gas centrifuge can be approximately described in regions away from the ends by Onsager's homogeneous pancake equation.1 Upon reformulation of the general problem, we find a new, simple and rigorous closed form, analytical solution by assuming a special separable solution and replacing the usual Ekman end cap boundary conditions with idealized impermeable, free slip boundary conditions. Then the flow may be described by an ordinary differential equation with solutions in terms of simple, classical functions. By identifying a small parameter, say ∊, defining the semi-long bowl approximation, and assuming a power series expansion in ∊, a sequence of asymptotic approximations to the master potential is obtained. Not surprisingly, the leading order term involves the well known ‘long bowl’ solution. Using the so-called ‘solving’ property of the 1-D pancake Green's function,2 we determine the next higher order solution. This recursive process is carried out on the computer to find all the terms up to O(∊4).Consequently, the solution of some complex rotating, viscous, heat conducting flow problems that normally require large mainframe computers can be better understood.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650060607
    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...