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This talk of calibration standards has brought up another question- where to get electrical reference standards for techniques such as scanning spreading resistance (SSRM) or scanning capacitance (SCM)? I'm talking about a stack of layers of known doping concentration and thicknesses of epitaxially grown silicon, usually set up as a sequence of
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We calibrate the XYZ scan axes of our AFM using a traceable height and pitch standard made of thermally grown silicon dioxide on silicon. The specimen contains these patterns: 10 um pitch, 2-dimensional array of pits, nominally 200 nm deep 2 um pitch, 1-dimensional array of ridges, same depth as the pits. The manufacturer's certificate of traceability
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I hope to know the cantilver temparture when operating AFM in room temperature. Does anyone know how much temparture increase by the laser? - For general, Al or gold coated cantilevers.
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We have had the exact same problem in our lab; that is, imaging DNA on mica in air, and finding particulates on the surface. We spent a long time trying to get to the bottom of it, and to the best of our knowledge the impurities actually come from two different sources. When making control samples incubated and washed with water from various sources
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Yes, the quality of miiliQ water can be rather low for low height, dry samples like DNA. Note that it depends a lot on how well the miiliQ machine is maintained! I've compared the quality of various waters, for this aplication, and the best is Sigma "Water for Molecular Biology" It's around 40 Euros a litre. This is mentioned at http
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You can use the method of counter-scanned images. The method allows correcting drift in SPM images (direct and counter) followed by matching the corrected images in a coincidence point (the common point for both images). Usually, after matching, the corrected images are averaged within the overlap area but you can subtract one image from another. Both
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We have used quite successfully Ultrapure MilliQ water for imaging of single molecules. If the filter cartridge/membrane were not changed as recommended, there is a good chance that water gets contaminated. We do not change those as frequently as the manufacturer recommends (too expensive), and therefore, we have to monitor quality of this water. We
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I have found that the image quality of adsorbates on mica (e.g. DNA molecules) depends on the purity of the water used to prepare solutions and to rinse the mica disks. I like to use water from a local Milli-Q system, but sometimes the water quality is not good enough. Can anyone suggest a commercial source of water?
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WSxM 4.0 Develop 13.0 allows this process. First of all you have to open both images. Then select in the menu: (1) Process -> Filter -> Align images. Press on "Select Images..." to choose the images to align and press OK in both dialog-boxes. (2) Process -> Zoom or Process -> Multiple Dynamic Zoom to trim the same area in both
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ou can do the comparison by performing cross-correlation. The coordinates of the maximum on the correlation image will give you the precise offset, calculated by statistical method. Then you can subtract one image from another, using calculated offset. All these operations can be performed in our software, FemtoScan Online. If you'd send me the