International Workshop on Electronic Crystals
ECRYS-99

J. Phys. IV France 09 (1999) Pr10-243-Pr10-246
DOI: 10.1051/jp4:19991061

Magnetic properties of the spin-density wave in (TMTSF)₂X and (TMTTF)₂Br

N. Matsunaga¹, Y. Hosokawa¹, H. Iwasaki¹, K. Nomura¹, S. Takasaki², J. Yamada², S. Nakatsuji², H. Anzai², T. Nakamura³, T. Takahashi⁴ and G. Saito<sup>5

1</sup>  Division of Physics, Hokkaido University, Sapporo 060-0810, Japan
²  Department of Material Science, Himeji Institute of Technology, Kamigohri, Hyogo 678-1297, Japan
³  Institute for Molecular Science, 444-8585, Japan
⁴  Department of Physics, Gakushuin University, Mejiro 1-5-1, Toshimaku, Tokyo 171-8588, Japan
⁵  Department of Chemistry, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan

Abstract
Magnetic properties of the spin density wave (SDW) phase in (TMTSF)₂X (X=AsF₆, PF₆) and (TMTTF)₂Br were investigated through analyses of ¹H-NMR and static magnetization measurements. A divergent peak was observed, at the temperature T* well below the SDW transition temperature, in the ¹H spin-lattice relaxation rate in the incommensurate SDW phase of (TMTSF)₂X. A decrease of the differential magnetic susceptibility of (TMTSF)₂X with the field parallel to the a-axis was observed around T*. This anomaly indicates a difference of the spin canting above and below T* which divides the SDW phase. In the measurements of magnetic susceptibility on the commensurate SDW phase of (TMTTF)₂Br, a large decrease of the spin susceptibility was observed above T_SDW and non-activated type behavior in the b'-axis susceptibility is observed below the spin-flop field at low temperature. The data are discussed on the basis of commensurability.

© EDP Sciences 1999