Regensburg 2013 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 31: Correlated Electrons: Low-Dimensional Systems -Materials 1
TT 31.3: Talk
Tuesday, March 12, 2013, 10:00–10:15, H41
Charge Density Wave Transport Properties of the (DCNQI-d6)2Cu radical anion salt — •Florian Hüwe1, Matthias Schmiddunser1, and Jens Pflaum1,2 — 1Experimental Physics VI, Julius-Maximilians University of Würzburg, 97074 Würzburg — 2ZAE Bayern, 97074 Würzburg
The class of organic metals provides intriguing examples of how the physical properties depend on the respective dimensionality of the underlying material system. The organic radical anion salt (DCNQI-d6)2Cu undergoes a pronounced first-order phase transition upon cooling from a highly conducting quasi-3D metallic state with a conductivity of σRT≈ 103S/cm into a quasi-1D semiconducting, commensurate charge density wave (CDW) state.
Our contribution reports on the transport properties of electrocrystallized (DCNQI)2Cu single crystals in this CDW regime. Below the phase transition temperature of Tc = 75 K the resistance of the about 2cm long needle-like samples increases more than five orders of magnitude along the [001]-direction of preferred conductivity. In addition, features of non-linear conduction occur above threshold fields of Eth ≈ 10−100 V/cm which we examined with respect to heating and interference effects by (pulsed) current-voltage and noise measurements. Small µ m-sized samples grown by microelectrolysis on a substrate with evaporated gold contacts allow for the investigation of electrical transport in the high-field limit. Finally, a connection between transport characteristics and charge carrier density is drawn.
Financial support by the DFG (project PF385/6-1) is gratefully acknowledged.