Publikationsdatum:
2015-04-28
Beschreibung:
The transition-metal dichalcogenides provided a good platform for the investigation of superconductivity and charge-density-wave (CDW) order. A series of high quality 6 R -TaS 2− x Se x (0 ≤ x ≤ 1.6) single crystals were fabricated by the chemical-vapor-transport method and systematically investigated. The CDW becomes more stable with more S being replaced by Se, which causes expansion of the lattice, and produces a negative chemical pressure in the system. The x dependence of the onset of superconductivity ( T c onset ) shows a dome-like shape with a maximum of T c onset = 2.7 K at x = 0.8. The magnetic susceptibility (4π χ ) of x = 0.8 under the hydrostatic pressure P = 1.0 GPa was also measured, which showed a small increase of T c and superconducting volume fraction. A pronounced peak effect was observed in the isothermal hysteresis with magnetic field ( H ) parallel to c -axis, which may arise from the quenching inhomogeneity and/or the stacking disorder. Finally, the evolution of the electronic states tuned by Se-doping was summarized in the phase diagram.
Print ISSN:
0021-8979
Digitale ISSN:
1089-7550
Thema:
Physik
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