The development of the scanning tunneling microscopy has led to the development of related techniques which include the scanning near-field microscopy (SNOM) and the scanning thermal microscopy (SThM). These techniques provide sample information in addition to the simultaneously obtained topography. With SNOM normal optical microscopy contrast mechanisms (adsorbance, fluorescence, polarization, etc.) can be used. The principles and design of a SNOM are presented. Subwavelength resolution (better than λ/20) is demonstrated. In SThM, the contrast is provided by temperature and thermal conductivity. The design of a resistive thermal probe is described. Several operating modes are described and image contrast due to thermal conductivity is demonstrated.
The temperature dependence of the proton and 19F NMR spectra of bis(7V,/V-diethylethylenediamine)copper(II) perchlorate, bis(7V,JV-diethylethylenediamine)copper(II) tetrafluoroborate, bis(7V,jV-diethylethylenediamine)nickel(II) perchlorate, and bis(lV,7V-diethylethylenediamine)nickel(II) tetrafluoroborate were studied. The second moments of the spectra show a sharp decrease at the temperature of the thermochromic phase transition. This decrease is due to the onset of dynamic motion in the ligand molecule. A model of the motion is described, and it is used with the crystallographic data to calculate the second moments for various amplitudes of the flipping motion. No narrowing of the 19F NMR line was observed.
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