https://doi.org/10.1007/s100510070207
Low frequency dielectric spectroscopy of the Peierls-Mott insulating state in the deuterated copper-DCNQI systems
1
Institute of Physics, PO Box 304, 10000 Zagreb, Croatia
2
Faculty of Civil Engineering, University of Maribor, 2000 Maribor, Slovenia
3
Physikalisches Institut, Universität Stuttgart, 70550 Stuttgart, Germany
Corresponding author: a stomic@ifs.hr
Received:
1
December
1999
Revised:
5
April
2000
Published online: 15 August 2000
We report a detailed characterization of an unique 3-fold commensurate insulating state in single crystals of the organic π - inorganic d hybrid Cu(DMe-DCNQI)2 systems with deuterated and partially deuterated DCNQI ring, by means of low-frequency dielectric spectroscopy. A broad relaxation mode of strength Δξ≈103-104 centred at vo≈1-10 kHz is observed in the hysteresis temperature region in which the insulating phase coexists with metallic islands. At lower temperatures, outside the nucleation range, the relaxation narrows, approaching a Debye-like form for an overdamped response of a system with a single degree of freedom. Both, the relaxation strength and the mean relaxation time (to=1/2πvo) are much larger than that expected for single-particle excitations. These features suggest the origin of the dielectric relaxation as an intrinsic property of the N = 3 charge density wave state.
PACS: 72.15.Nj – Collective modes, (e.g., in one-dimensional conductors) / 71.45.Lr – Charge-density-wave systems / 71.30.+h – Metal-insulator transitions and other electronic transitions / 77.22.Gm – Dielectric loss and relaxation
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000
