Abstract-Anisotropic terahertz dielectric responses of sodium nitrate crystal

Xiaojian Fu,   Youting Song,   Chang Qing Sun and   Ji Zhou  

Phys. Chem. Chem. Phys., 2014, Accepted Manuscript

DOI: 10.1039/C3CP55484H
Received 28 Dec 2013, Accepted 18 Feb 2014
First published online 18 Feb 2014
http://pubs.rsc.org/en/content/articlelanding/2014/cp/c3cp55484h#!divAbstract

Terahertz (THz) spectroscopy has become an effective tool to characterize the low-frequency rotational and vibrational modes of molecules. In addition, novel THz dielectric responses and optical properties on the basis of molecular rotation and vibration have attracted lots of attention because of their potential application in THz devices. In this paper, the dielectric response of low-symmetric sodium nitrate crystal in the frequency range of 0.2-1.5 THz was experimentally demonstrated. Four absorption bands at 0.23, 0.47, 0.92, and 1.15 THz were observed in the dielectric spectra and were tentatively ascribed to the rotational motion of nitrate ions. Based on the molecular rotation mechanism, the dielectric anisotropy and dielectric resonance of the crystal were discussed in detail.