Anomalous transport properties and phase diagram of the FeAs-based SmFeAsO1-xFx superconductors.
We report the detailed phase diagram and anomalous transport properties of Fe-based high-T_{c} superconductors SmFeAsO1-xFx. It is found that superconductivity emerges at x approximately 0.07, and optimal doping takes place in the x approximately 0.20 sample with the highest T_{c} approximately 54 K. T_{c} increases monotonically with doping; the anomaly in resistivity from structural phase or spin-density-wave order is rapidly suppressed, suggesting a quantum critical point around x approximately 0.14. As manifestations, a linear temperature dependence of the resistivity shows up at high temperatures in the x<0.14 regime but at low temperatures just above T_{c} in the x>0.14 regime; a drop in carrier density evidenced by a pronounced rise in the Hall coefficient is observed below the temperature of the anomaly peak in resistivity. A scaling behavior is observed between the Hall angle and temperature: cottheta_{H} proportional, variantT;{1.5} for all samples with different x in SmFeAsO1-xFx system.
Liu
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Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
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Wu
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Fang
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Chen
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Li
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Liu
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Xie
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Wang
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Yang
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Ding
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Feng
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Chen
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