Out-of-plane dielectric constant of θ-(BEDT-TTF)2RbZn(SCN)4 single crystal

The out-of-plane dielectric constant g of the quasi-two-dimensional organic conductor theta-(BEDT-TTF)(2)RbZn(SCN)(4), which exhibits a metal-insulator transition at 190 K, was measured and analyzed from 100 to 300 K in the frequency range 10(3)-10(8) Hz. Most unexpectedly e is found to show a significant dielectric relaxation above 190 K, which suggests that insulating and metallic phases coexist above 190 K. (C) 2002 Elsevier Science B.V. All rights reserved.