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Full-Text Articles in Physics
The Spectral Function Of Random Resistor Networks, Anthony Day, M. Thorpe
The Spectral Function Of Random Resistor Networks, Anthony Day, M. Thorpe
Anthony Roy Day
The effective complex conductivity [...] of a two-component material can be conveniently expressed as an integral transformation of a spectral function. The spectral function depends only on the geometry of the material, and can be used to calculate [...] for any particular choice of component conductivities. This is a very useful feature if the component conductivities can be varied (by changing the temperature or frequency, for example) at a fixed geometry. We present a derivation of the spectral function that identifies it as a density of states. We have made direct numerical calculations of the spectral function of two-dimensional random …
Scanning Local‐Acceleration Microscopy, Nancy Burnham, A. Kulik, G. Gremaud, P. Gallo, F. Oulevey
Scanning Local‐Acceleration Microscopy, Nancy Burnham, A. Kulik, G. Gremaud, P. Gallo, F. Oulevey
Nancy A. Burnham
By adapting a scanning force microscope to operate at frequencies above the highest tip–sample resonance, the sensitivity of the microscope to materials’ properties is greatly enhanced. The cantilever’s behavior in response to high‐frequency excitation from a transducer underneath the sample is fundamentally different than to its low‐frequency response. In this article, the motivations, instrumentation, theory, and first results for this technique are described.
Materials’ Properties Measurements: Choosing The Optimal Scanning Probe Microscope Configuration, Nancy Burnham, G Gremaud, A Kulik, P Gallo, F Oulevey
Materials’ Properties Measurements: Choosing The Optimal Scanning Probe Microscope Configuration, Nancy Burnham, G Gremaud, A Kulik, P Gallo, F Oulevey
Nancy A. Burnham
Rheological models are used to represent different scanning probe microscope configurations. The solutions for their static and dynamic behavior are found and used to analyze which scanning probe microscope configuration is best for a given application. We find that modulating the sample at high frequencies results in the best microscope behavior for measuring the stiffness of rigid materials, and that by modulating the tip at low frequencies and detecting the motion of the tip itself (not its position relative to the tip holder) should be best for studying compliant materials in liquids.