TY - JOUR
T1 - Observation of cusps in irreversible vortex states of κ-(BEDT-TTF)2Cu(NCS)2 single crystals
AU - Kawamata, S.
AU - Okuda, K.
AU - Sasaki, T.
AU - Toyota, N.
PY - 1994/3
Y1 - 1994/3
N2 - Magnetic torque of a quasi two-dimensional superconductor κ-(BEDT-TTF)2Cu(NCS)2 was measured as a function of field direction θ with respect to the a*-axis under several magnetic fields H up to 8 kOe in the temperature range from 1.3 to 8 K. A sharp cusp C1 in the irreversible vortex region was found at θc1 near H∥bc-plane between 1.3 and 7 K. In addition, extra cusps C2 and C3 were also observed at θc2 and θc3, respectively, between 2.5 and 6 K. At each temperature, the perpendicular component of H to give each cusp is kept constant as: H cos θcn const. HcPn (n = 1, 2, 3), i.e., cusps C1, C2 and C3 are ruled by the characteristic field perpendicular to the bc-plane HcP1, HcP2 and HcP3, respectively. These behaviors are almost the same as those we reported previously on the oxide superconductor Bi2Sr2CaCu2O8 (Bi2212). The results reveal that the cusp effect is intrinsic for these layered superconductors.
AB - Magnetic torque of a quasi two-dimensional superconductor κ-(BEDT-TTF)2Cu(NCS)2 was measured as a function of field direction θ with respect to the a*-axis under several magnetic fields H up to 8 kOe in the temperature range from 1.3 to 8 K. A sharp cusp C1 in the irreversible vortex region was found at θc1 near H∥bc-plane between 1.3 and 7 K. In addition, extra cusps C2 and C3 were also observed at θc2 and θc3, respectively, between 2.5 and 6 K. At each temperature, the perpendicular component of H to give each cusp is kept constant as: H cos θcn const. HcPn (n = 1, 2, 3), i.e., cusps C1, C2 and C3 are ruled by the characteristic field perpendicular to the bc-plane HcP1, HcP2 and HcP3, respectively. These behaviors are almost the same as those we reported previously on the oxide superconductor Bi2Sr2CaCu2O8 (Bi2212). The results reveal that the cusp effect is intrinsic for these layered superconductors.
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U2 - 10.1016/0038-1098(94)90359-X
DO - 10.1016/0038-1098(94)90359-X
M3 - Article
AN - SCOPUS:0028393202
SN - 0038-1098
VL - 89
SP - 955
EP - 958
JO - Solid State Communications
JF - Solid State Communications
IS - 11
ER -