Subterahertz electrodynamics of (TMTSF)(2)X (X = ClO4, PF6) salts
2013 (English)In: Journal of Experimental and Theoretical Physics, ISSN 1063-7761, E-ISSN 1090-6509, Vol. 116, no 3, 460-466 p.Article in journal (Refereed) Published
The terahertz-subterahertz spectra of the complex permittivity and dynamic conductivity of polycrystalline (TMTSF)(2)ClO4 and (TMTSF)(2)PF6 samples are measured quantitatively. The spectra of (TMTSF)(2)ClO4 have absorption lines at frequencies of 7 and 30 cm(-1). The obtained temperature dependences of the line parameters in the range 5-300 K cast some doubt on the earlier concept of their phonon origin. An excitation is detected at temperatures below 20 K in the frequency range near 30 cm(-1), and its nature is related to the activation of a transverse acoustic phonon caused by the folding of the Brillouin zone due to the ordering of noncentrosymmetrical anions below 20 K. An increase in the carrier relaxation rate is found in this temperature range, which indicates a close relation between the electron and phonon subsystems in (TMTSF)(2)ClO4. Sings of additional low-energy excitations that should manifest themselves at frequencies below 1-2 cm(-1) are detected. (TMTSF)(2)PF6 containing centrosymmetrical anions has no absorption lines in the frequency range 3-20 cm(-1) and the temperature range 5-300 K.
Place, publisher, year, edition, pages
2013. Vol. 116, no 3, 460-466 p.
IdentifiersURN: urn:nbn:se:su:diva-91320DOI: 10.1134/S1063776113030163ISI: 000317979700011OAI: oai:DiVA.org:su-91320DiVA: diva2:633307