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On the contrast in eddy current microscopy using atomic force microscopes
Author(s) -
Hirsekorn S.,
Rabe U.,
Boub A.,
Arnold W.
Publication year - 1999
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/(sici)1096-9918(199905/06)27:5/6<474::aid-sia528>3.0.co;2-h
Subject(s) - cantilever , amplitude , vibration , eddy current , microscope , dipole , phase (matter) , atomic force acoustic microscopy , magnetic force microscope , chemistry , non contact atomic force microscopy , microscopy , physics , optics , noise (video) , computational physics , condensed matter physics , materials science , kelvin probe force microscope , acoustics , magnetic field , quantum mechanics , magnetization , composite material , image (mathematics) , artificial intelligence , computer science
A magnetic probe of an atomic force microscope oscillating above asample induces eddy currents within conducting materials. Theresulting electrodynamic interaction between sample and probeinfluences the probe vibrations so that local variations inconductivity of a sample might be imaged with an atomic forcemicroscope by phase shifts and/or amplitude changes of the probevibrations. A quantitative evaluation of this effect allows one tojudge whether the local conductivity can be measured. This paperpresents the calculation of attainable contrast in phase and inamplitude images by measuring the high‐frequency flexuralvibrations of a rectangular beam cantilever. For the sensor tipdimensions of available cantilevers, the dipole approximation turnedout not to be valid but the monopole approximation yields areasonable estimation of the contrast. Calculations based on themonopole approximation show that the amplitude and the phase changesof the cantilever vibration ensuing from samples with conductivitychanges of 20 MS m −1 are below the thermal noiselevel. Copyright © 1999 John Wiley & Sons, Ltd.