Raman studies of the charge ordering and semiconductor-metal phase transition in polymorphic forms of (BEDT-TTF)$_{2}$Br$_{1.3}$I$_{1.1}$Cl$_{0.6}$

R. Wojciechowski; A. Kowalska; J. Ulanski; M. Mas-Torrent; E. Laukhina; C. Rovira; V. Tkacheva; K. Yamamoto; K. Yakushi

doi:doi:10.1051/jp4:2004114094

Issue		J. Phys. IV France Volume 114, April 2004


Page(s)		393 - 395
DOI		https://doi.org/10.1051/jp4:2004114094

J. Phys. IV France 114 (2004) 393
DOI: 10.1051/jp4:2004114094

Raman studies of the charge ordering and semiconductor-metal phase transition in polymorphic forms of (BEDT-TTF) ₂Br_1.3I_1.1Cl_0.6

R. Wojciechowski^{1, 1}, A. Kowalska¹, J. Ulanski¹, M. Mas-Torrent², E. Laukhina², C. Rovira², V. Tkacheva³, K. Yamamoto⁴ and K. Yakushi⁴

¹ Department of Molecular Physics, Technical University of Lodz, 90-924 Lodz, Poland
² Institut de Ciencia de Materials de Barcelona, Campus UAB, 08193, Barcelona, Spain
³ Institute of Problems of Chemical Physics, RAS, 142432 Chernogolovka, MD, Russia
⁴ Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan

Abstract
Semiconductor to metal and semiconductor to insulator phase transitions in the $\alpha$ " $\!$ '- and $\alpha$ '-(ET) ₂Br _1.3I _1.1Cl _0.6 single crystals were investigated by Raman spectroscopy. A charge ordered nature of the insulating state of the $\alpha$ '-phase was confirmed. For the metallic $\beta$ "-phase ( $\alpha$ " $\!$ ' above 185 K) the Raman spectrum shows more bands than expected from the number of the C=C stretching a _g modes. Key words. Organic conductors, Raman spectroscopy, charge order.

Raman studies of the charge ordering and semiconductor-metal phase transition in polymorphic forms of (BEDT-TTF) 2Br1.3I1.1Cl0.6

Raman studies of the charge ordering and semiconductor-metal phase transition in polymorphic forms of (BEDT-TTF) ₂Br_1.3I_1.1Cl_0.6