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YBa2Cu3O7-δ (YBCO) thin films on SrTiO3,
imaged by scanning force microscopy
The c lattice constant of YBCO is about 1.1 nm. Thin films which
are well oriented usually show steps and sometimes growth spirals
with a step height of this value.
Topographic signal,
image size 2 µm, height scale 20 nm. Instrument: Digital
Instruments Nanoscope IIIa Multimode, in Tapping Mode.
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The steps can more easily be seen in the derivative of the topographic signal, or in the error signal.
Error signal image, image size 5 µm. Instrument: Park Scientific Instruments Autoprobe CP, in Intermittent Contact Mode. |
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Image mosaic of a grain boundary in YBCO
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YBa2Cu3O7-x film grown on a 24° SrTiO3 symmetric bicrystal substrate by pulsed laser deposition
Film thickness approx. 330 nm
Sample No. B009 (April 1998)
AFM
Park AutoprobeTM CP
Multitask head, with 100 µm scanner and Scan MasterTM
AFM Imaging
ambient conditions
Intermittent contact mode
Mosaic of 13 AFM images
Image width: 2.5 µm
z scale
50 nm
0 nm
The actively linearized xy-scan of the instrument allows to follow the grain boundary over tens of microns and to create a mosaic of several images.
The grain boundary is slightly faceted (about 100 nm max. deviation from the straight line).
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Other examples include some nice AFM images of ionic crystals on a larger scale.
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