The Experts below are selected from a list of 53187 Experts worldwide ranked by ideXlab platform
Elisabeth Soergel - One of the best experts on this subject based on the ideXlab platform.
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Impact of the tip radius on the Lateral Resolution in piezoresponse force microscopy
New Journal of Physics, 2008Co-Authors: Tobias Jungk, A. Hoffmann, Elisabeth SoergelAbstract:We present a quantitative investigation of the impact of tip radius as well as sample type and thickness on the Lateral Resolution in piezoresponse force microscopy (PFM) investigating bulk single crystals. The observed linear dependence of the width of the domain wall on the tip radius as well as the independence of the Lateral Resolution on the specific crystal-type are validated by a simple theoretical model. Using a Ti-Pt-coated tip with a nominal radius of 15 nm the so far highest Lateral Resolution in bulk crystals of only 17 nm was obtained.
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impact of the tip radius on the Lateral Resolution in piezoresponse force microscopy
New Journal of Physics, 2008Co-Authors: Tobias Jungk, A. Hoffmann, Elisabeth SoergelAbstract:We present a quantitative investigation of the impact of tip radius as well as sample type and thickness on the Lateral Resolution in piezoresponse force microscopy (PFM) investigating bulk single crystals. The observed linear dependence of the apparent width of a ferroelectric domain wall on the tip radius as well as the independence of the Lateral Resolution on the specific crystal-type are validated by a simple model. Using a Ti-Pt coated tip with a nominal radius of 15 nm the so far highest Lateral Resolution in bulk crystals of only 17 nm was obtained.
Derecke Palmer - One of the best experts on this subject based on the ideXlab platform.
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Exploiting Lateral Resolution of near-surface seismic refraction methods
Journal of Earth Science, 2009Co-Authors: Derecke PalmerAbstract:The 1D τ-p inversion algorithm is widely employed to generate starting models with most computer programs that implement refraction tomography. However, this algorithm emphasizes the vertical Resolution of many layers, and as a result, it frequently fails to detect even large Lateral variations in seismic velocities, such as the decreases that are indicative of shear zones. This study presents a case that demonstrates the failure of the 1D τ-p inversion algorithm to define or even detect a major shear zone that is 50 m or ten stations wide. Furthermore, the majority of refraction tomography programs parameterize the seismic velocities within each layer with vertical velocity gradients. By contrast, the 2D generalized reciprocal method (GRM) inversion algorithms emphasize the Lateral Resolution of individual layers. This study demonstrates the successful detection and definition of the 50-m wide shear zone with the GRM inversion algorithms. The existence of the shear zone is corroborated by a 2D analysis of the head wave amplitudes and by numerous closely spaced orthogonal seismic profiles carried out as part of a later 3D refraction investigation. Furthermore, a 1D analysis of the head wave amplitudes indicates that a reversal in the seismic velocities, rather than vertical velocity gradients, occurs in the weathered layers. While all seismic refraction operations should aim to provide as accurate depth estimates as is practical, the major conclusion reached in this study is that refraction inversion algorithms that emphasize the Lateral Resolution of individual layers generate more useful results for geotechnical and environmental applications. The advantages of the improved Lateral Resolution are obtained with 2D profiles in which the structural features can be recognized from the magnitudes of the variations in the seismic velocities. Furthermore, the spatial patterns obtained with 3D investigations facilitate the recognition of structural features that do not display any intrinsic variation or “signature” in seismic velocities.
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Maximising the Lateral Resolution of near-surface seismic refraction methods
Exploration Geophysics, 2009Co-Authors: Derecke PalmerAbstract:The tau-p inversion algorithm is widely employed to generate starting models with most computer programs, which implement refraction tomography. Thisalgorithm emphasises thevertical Resolution of manylayers, andas a result, it frequentlyfailstodetectevenlargeLateralvariationsinseismicvelocities,suchasthedecreaseswhichareindicativeofshear zones.Thisstudydemonstratesthefailureofthetau-pinversionalgorithmtodetectordefineamajorshearzonewhichis50m or 10 stations wide. Furthermore, themajority of refraction tomography programs parameterise the seismic velocities within each layer with vertical velocity gradients. By contrast, the Generalized Reciprocal Method (GRM) inversion algorithms emphasise the Lateral Resolution of individual layers. This study demonstrates the successful detection and definition of the 50m wide shear zone with the GRMinversionalgorithms.Theexistenceoftheshearzoneisconfirmedbya2Danalysisoftheheadwaveamplitudesandby numerouscloselyspacedorthogonalseismicprofilescarriedoutaspartofalater3Drefractioninvestigation.Furthermore,an analysisoftheshotrecordamplitudesindicatesthatareversalintheseismicvelocities,ratherthanverticalvelocitygradients, occurs in the weathered layers. Themajorconclusionreachedinthisstudyisthatwhileallseismicrefractionoperationsshouldaimtoprovideasaccurate depthestimatesasispractical,thosewhichemphasisetheLateralResolutionofindividuallayersgeneratemoreusefulresultsfor geotechnical and environmental applications. The advantages of the improved Lateral Resolution are obtained with 2D traverses in which the structural features can be recognised from the magnitudes of the variations in the seismic velocities. Furthermore,thespatialpatternsobtainedwith3Dinvestigationsfacilitatetherecognitionofstructuralfeaturessuchasfaults which do not display any intrinsic variation or 'signature' in seismic velocities.
Achim Walter Hassel - One of the best experts on this subject based on the ideXlab platform.
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Lateral Resolution in scanning Kelvin probe microscopy
Corrosion Science, 2016Co-Authors: Mariusz Wicinski, Wolfgang Burgstaller, Achim Walter HasselAbstract:Abstract The Lateral Resolution of a scanning Kelvin probe (SKP) is a key parameter for investigating microstructures. It depends on two main device parameters, the tip diameter and the tip sample distance. Variation of them affects physical parameters like stray capacitance and signal intensity. A model sample with a sharp border between two materials of different work function (Al/Cu) has been produced. Line-scans perpendicular to the Al–Cu edge show the influence of tip diameters and tip-sample gaps. A mathematical expression for the maximum Lateral Resolution was derived by the method of images. These calculations are in good agreement with systematic measurements.
Tobias Jungk - One of the best experts on this subject based on the ideXlab platform.
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Impact of the tip radius on the Lateral Resolution in piezoresponse force microscopy
New Journal of Physics, 2008Co-Authors: Tobias Jungk, A. Hoffmann, Elisabeth SoergelAbstract:We present a quantitative investigation of the impact of tip radius as well as sample type and thickness on the Lateral Resolution in piezoresponse force microscopy (PFM) investigating bulk single crystals. The observed linear dependence of the width of the domain wall on the tip radius as well as the independence of the Lateral Resolution on the specific crystal-type are validated by a simple theoretical model. Using a Ti-Pt-coated tip with a nominal radius of 15 nm the so far highest Lateral Resolution in bulk crystals of only 17 nm was obtained.
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impact of the tip radius on the Lateral Resolution in piezoresponse force microscopy
New Journal of Physics, 2008Co-Authors: Tobias Jungk, A. Hoffmann, Elisabeth SoergelAbstract:We present a quantitative investigation of the impact of tip radius as well as sample type and thickness on the Lateral Resolution in piezoresponse force microscopy (PFM) investigating bulk single crystals. The observed linear dependence of the apparent width of a ferroelectric domain wall on the tip radius as well as the independence of the Lateral Resolution on the specific crystal-type are validated by a simple model. Using a Ti-Pt coated tip with a nominal radius of 15 nm the so far highest Lateral Resolution in bulk crystals of only 17 nm was obtained.
Geraint Williams - One of the best experts on this subject based on the ideXlab platform.
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Probe diameter and probe-specimen distance dependence in the Lateral Resolution of a scanning Kelvin probe
Journal of Applied Physics, 2002Co-Authors: Hamilton Neil Mcmurray, Geraint WilliamsAbstract:The ability of a scanning Kelvin probe (SKP) to resolve Lateral differences in specimen surface potential is investigated by two routes. First, electrostatic calculations are used to obtain analytical expressions for the maximum Lateral Resolution attainable by a “point probe” of negligible physical dimensions, as a function of probe–specimen distance. Second, Lateral Resolution is measured experimentally by scanning plane-ended cylindrical probes of varying diameters at varying heights across a linear edge, delimiting two electrically continuous coplanar areas of dissimilar metal. Finally the two approaches are combined to obtain a semiempirical relationship between probe diameter, probe–specimen distance, and Lateral Resolution for plane-ended cylindrical probes. An expression is also developed for the minimum error to be expected in a surface potential measurement when this is associated with a specimen feature exhibiting a diameter comparable with the probe–specimen distance.
