We study the current-voltage (I-V) characteristics in a quasi-two-dimensional, π-d coupled organic conductor λ-(BEDT-TSF)2FeCl4 which undergoes a metal-to-insulator transition associated with an antiferromagnetic ordering at TMI = 8.3 K. Drastic nonlinear transport phenomena are observed in the I-V curve, revealing a so-called negative resistance effect at an applied electric field or a current density higher than threshold ET or JT. The overall I-V curves are quite well explained phenomenologically by a nonlinear equation for a positive feedback system that the nonlinear conductivity proportional to Jn with n = 1.4(×0.1). This indicates that some carrier decondensation mechanism works in the present antiferromagnetic insulator. Discussions are presented by following quite similar nonlinear phenomena observed in a variety of quasi-one-dimensional, mixed-stack, and segregated-stack, organic insulators.
|Number of pages||4|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2002 Jul 15|