Dielectric spectroscopy frequency band

Further insight into histidine encapsulation of nanoclusters (Au, Ag, Cu, Pt) was provided by infrared spectroscopy. IR spectra of free histidine showed a set of stretching bands for the N-H bond of the amine and strong peaks (1630 cm, 1413 cm ) attributed to an asymmetrical and symmetrical C02 stretch. As a result of nanocluster stabilization and the subsequent formation of a metal-N(His) interface, the N-H stretching frequencies broadened and the number of bands decreased relative to free histidine due to the interactions with the dielectric field at the nanocluster surface. ... 

There is a clear difference between microwave spectroscopy and microwave dielectric heating effects. Thus, in microwave spectroscopy, molecules are examined in the gas phase and the microwave spectrum for a molecule exhibits many sharp bands [15] over the frequency range 3-60 GHz. Such sharp bands arise from transitions between quantized rotational states of the molecules. Microwave spectroscopy provides an excellent fingerprinting method for identifying molecules in a gas phase and has been used, for example, to confirm the presence of a wide range of molecules in outer space. 

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