Library

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
    Evidence for increased chain stiffness of polydiacetylene in solution (1988)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 89 (1988), S. 6477-6483 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Evidence has been found of increased chain stiffness of isolated polydiacetylene molecules in solution, associated to an increased side-group interaction, and in at least one case, to an increased and more temperature dependent electronic conjugation length: Bromoform solutions of poly-3BCMU (3B) and poly-4BCMU (4B) were studied by visible and IR absorption spectroscopy and by small angle neutron scattering. The polymers are more rigid than in other solvents: for 3B, b〉600 A(ring) at 45 °C and for 4B, b=420±40 A(ring) at 25 °C. Hydrogen bonding between neighboring side groups is observed, decreasing upon increasing temperature. For 3B, the visible absorption spectrum is slightly red shifted, the more so the lower the temperature, indicating an influence of chain stiffness on electronic conjugation length.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.455367
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Stability of an oscillating tip in noncontact atomic force microscopy: Theoretical and numerical investigations (2002)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 91 (2002), S. 2537-2543 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: This article is a theoretical and a numerical investigation of the stability of a tip–cantilever system used in noncontact atomic force microscopy (NC-AFM) when it oscillates close to a surface. No additional dissipative force is considered. The theoretical approach is based on a variational method exploiting a coarse grained operation that gives the temporal dependence of the nonlinear coupled equations of motion in amplitude and phase of the oscillator. Stability criterions for the resonance peak are deduced and predict a stable behavior of the oscillator in the vicinity of the resonance. The numerical approach is based on results obtained with a virtual NC-AFM developed in our group. The effect of the size of the stable domain in phase is investigated. These results are in particularly good agreement with the theoretical predictions. They also show the influence of the phase shifter in the feedback loop and the way in which it can affect the damping signal. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1428084
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Comments on the use of the force mode in atomic force microscopy for polymer films (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 754-762 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Atomic force microscopy (A.F.M.) was first described as a powerful technique for studying insulating, hard surfaces. Since then, it has also been considered as an appropriate technique for investigating, at a submicromic scale, elastic and viscoelastic properties of soft materials as polymer films. An attempt is made to show how macroscopic models can be fruitfully employed in order to interpret the force curves obtained in AFM on polymer films. Through an analysis of the slope variation and the way the instability occurs at the tip-sample contact, it is shown that a macroscopic approach is a useful way to explain most of the features of the force curves. Furthermore the importance is underlined of the initial conditions. It is shown that for polymer samples which have a stiffness within the range of the probe one, drastic changes of the force curve shape can occur when the initial conditions vary. Finally, this approach should allow one to clarify the conditions for which the macroscopic approach fails.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.357777
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Oscillation of the cantilever in atomic force microscopy: Probing the sample response at the microsecond scale (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 82 (1997), S. 3652-3660 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The relaxation of an atomic force microscope microlever is investigated after the unsticking instability. We show that the different oscillating behavior can be explained by considering that polymer chains remain stuck at the tip even when the microlever is away from the sample. A simple rheological model is used which satisfactorily describes the different features observed. The approach described in the article provides useful additional information to understand the behavior of a microlever coupled to a polymer network. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.365727
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Elastic misfit stress relaxation in highly strained InGaAs/GaAs structures (1994)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 65 (1994), S. 1162-1164 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The strain contrasts associated with three-dimensional coherently strained islands formed during the epitaxial growth of highly strained In0.45Ga0.55As layers on GaAs (001) have been studied by transmission electron microscopy. It is demonstrated that the comparison of these experimental strain contrasts with simulated profiles makes it possible to assess the elastic relaxation of the islands.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.112128
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Nonlinear dynamical properties of an oscillating tip–cantilever system in the tapping mode (1999)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 111 (1999), S. 1615-1627 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The dynamical properties of an oscillating tip–cantilever system are now widely used in the field of scanning force microscopy. The aim of the present work is to get analytical expressions describing the nonlinear dynamical properties of the oscillator in noncontact and intermittent contact situations in the tapping mode. Three situations are investigated: the pure attractive interaction, the pure repulsive interaction, and a mixing of the two. The analytical solutions obtained allow general trends to be extracted: the noncontact and the intermittent contact show a very discriminate variation of the phase. Therefore the measurement of the phase becomes a simple way to identify whether or not the tip touches the surface during the oscillating period. It is also found that the key parameter governing the structure of the dynamical properties is the product of the quality factor by a reduced stiffness. In the attractive regime, the reduced stiffness is the ratio of an attractive effective stiffness and the cantilever one. In the repulsive regime, the reduced stiffness is the ratio between the contact stiffness and the cantilever one. The quality factor plays an important role. For large values of the quality factor; it is predicted that a pure topography can be obtained whatever the value of the contact stiffness. For a smaller quality factor, the oscillator becomes more sensitive to change of the local mechanical properties. As a direct consequence, varying the quality factor, for example with a vacuum chamber, would be a very interesting way to investigate soft materials either to access topographic information or nanomechanical properties. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.479422
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Influence of noncontact dissipation in the tapping mode: Attempt to extract quantitative information on the surface properties with the local force probe method (2001)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 114 (2001), S. 4945-4954 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: In the Tapping mode, a variation of the oscillation amplitude and phase as a function of the tip sample distance is the necessary measurement to access quantitatively to the properties of the surface. In the present work, we give a systematic comparison between experimental data recorded on two surfaces, phase and amplitude, and theoretical curves. With an interaction between the tip and the surface taking into account an attractive and a repulsive term, the analytical approach is unable to properly describe the relationship between the phase variation and the oscillation amplitude variation. When an additional dissipation term is involved, due to the attractive interaction between the tip and the surface, the model gives a good agreement with the recorded data. Particularly, the trends in the phase variations related to the noncontact situations have been found to be amenable to an analysis based upon a simple viscoelastic behavior of the surface. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1349179
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Study of reactive diacetylenes: structure of monomer and polymer pFBS crystals (1988)
    Copenhagen : International Union of Crystallography (IUCr)
    Acta crystallographica 44 (1988), S. 617-624 
    Details
    ISSN: 1600-5740
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0108768188007724
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Stability criterions of an oscillating tip-cantilever system in dynamic force microscopy (2001)
    Springer
    The European physical journal 24 (2001), S. 221-229 
    Details
    ISSN: 1434-6036
    Keywords: PACS. 05.45.-a Nonlinear dynamics and nonlinear dynamical systems – 07.79.Lh Atomic force microscopes – 45.20.Jj Lagrangian and Hamiltonian mechanics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract: This work is a theoretical investigation of the stability of the non-linear behavior of an oscillating tip-cantilever system used in dynamic force microscopy. Stability criterions are derived that may help to a better understanding of the instabilities that may appear in the dynamic modes, Tapping and NC-AFM, when the tip is close to a surface. A variational principle allows to get the temporal dependence of the equations of motion of the oscillator as a function of the non-linear coupling term. These equations are the basis for the analysis of the stability. One find that the branch associated to frequencies larger than the resonance is always stable whereas the branch associated to frequencies smaller than the resonance exhibits two stable domains and one unstable. This feature allows to re-interpret the instabilities appearing in Tapping mode and may help to understand the reason why the NC-AFM mode is stable.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100510170009
    Library Location Call Number Volume/Issue/Year 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...