Regensburg 2010 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 5: CE: Low-dimensional Systems - Materials 1
TT 5.2: Vortrag
Montag, 22. März 2010, 14:30–14:45, H18
Exploring the doping dependence of the Mott transition on X-ray irradiated crystals of κ-(ET)2Cu[N(CN)]2]Cl — •Ulrich Tutsch1, Ammar Naji1, Takahiko Sasaki2, and Michael Lang1 — 1Physikalisches Institut, Goethe-Universität Frankfurt (M), SFB/TRR49, D-60438 Frankfurt (M) — 2Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
The quasi two-dimensional organic charge-transfer salt κ-(ET)2Cu[N(CN)2]Cl has a Mott-insulating ground state at ambient pressure, which can be transformed into a superconducting ground state (Tc≈13 K) by applying moderate pressures of ∼ 30 MPa (300 bar). Our objective is to study how the first-order Mott-transition line and its second-order critical end point change on doping the material away from half filling. We use X-ray irradiation in order to introduce charge carriers in this material [1] and take the shifts in the room-temperature resistivity as a measure of the amount of doping. We will present resistivity data for the temperature range 5 K ≤ T≤60 K and for pressures up to 50 MPa for a κ-(ET)2Cu[N(CN)]2]Cl crystal at various doping levels and discuss the accompanied changes in the p-T-phase diagram.
[1] T. Sasaki et al., J. Phys. Soc. Jpn. 76, 123701 (2007)