The novel role of anion ordering in angle dependent magnetotransport of one-dimensional organic conductors

Abstract

We have studied the angle dependent magnetoresistance of the various Bechgaard salts when the magnetic field rotates in the b'c* plane. Lebed-type resonance is clearly observed for all the compounds both in Rxx and in Rzz. In all cases, conductivity is enhanced at angles proposed by Lebed. (TMTSF)2ClO4 shows almost the same behavior as (TMTSF)2PF6 in spite of the presence of anion ordering. Only considered is doubling of unit cell along the intermediate conducting direction (b). Conductivity enhancement is very much pronounced in Rzz than in Rxx. The resonance effect is particularly well established in Rzz of (TMTSF)2ReO4 where more than seventh resonance can be easily observed. The angles at which resonance takes place can be fitted with the general formula, but only with p/q=odd integers. Also found are additional fast oscillatory parts superposed on the Lebed oscillations. © 2002 Elsevier Science B.V. All rights reserved.