TY - JOUR
T1 - The effect of Pb doping in HgBa2Ca2Cu3O8+δ superconductor
AU - Isawa, Kazuyuki
AU - Tokiwa-Yamamoto, Ayako
AU - Itoh, Makoto
AU - Adachi, Seiji
AU - Yamauchi, H.
PY - 1993/11/10
Y1 - 1993/11/10
N2 - Polycrystalline samples with the starting compositions of (Hg0.8Pb0.2)xBa2Ca2Cu3O8+δ (1.0≤x≤2.5) were prepared under various synthetic conditions. Both powder X-ray-diffraction analysis and energy dispersive X-ray spectroscopy revealed that the Pb ions were successfully doped into the Hg-1223 phase. High-quality Pb-doped Hg-1223 samples for the starting composition with x=1.5 were obtained when heated at 675°C only for 1 h. The resistivity (ρ{variant}) of such a sample was low, being ∼8×103 Ω cm at 300 K, and the ρ{variant} versus T curve was linearly extrapolated to zero resistance at 0 K, being similar to the cases of high-quality high-Tc cuprates. The zero resistance due to superconductivity started at 122.2 K. When the sample was reduced in flowing argon gas, it exhibited a Meissner signal below 132 K and its Meissner volume fraction exceeded 20% at 5 K. According to thermoelectric power measurements, the carrier density in the sample was reversibly dependent on the oxygen partial pressure, and the sample post-annealed in flowing oxygen gas was likely overdoped.
AB - Polycrystalline samples with the starting compositions of (Hg0.8Pb0.2)xBa2Ca2Cu3O8+δ (1.0≤x≤2.5) were prepared under various synthetic conditions. Both powder X-ray-diffraction analysis and energy dispersive X-ray spectroscopy revealed that the Pb ions were successfully doped into the Hg-1223 phase. High-quality Pb-doped Hg-1223 samples for the starting composition with x=1.5 were obtained when heated at 675°C only for 1 h. The resistivity (ρ{variant}) of such a sample was low, being ∼8×103 Ω cm at 300 K, and the ρ{variant} versus T curve was linearly extrapolated to zero resistance at 0 K, being similar to the cases of high-quality high-Tc cuprates. The zero resistance due to superconductivity started at 122.2 K. When the sample was reduced in flowing argon gas, it exhibited a Meissner signal below 132 K and its Meissner volume fraction exceeded 20% at 5 K. According to thermoelectric power measurements, the carrier density in the sample was reversibly dependent on the oxygen partial pressure, and the sample post-annealed in flowing oxygen gas was likely overdoped.
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U2 - 10.1016/0921-4534(93)90788-R
DO - 10.1016/0921-4534(93)90788-R
M3 - Article
AN - SCOPUS:0027699494
VL - 217
SP - 11
EP - 15
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
SN - 0921-4534
IS - 1-2
ER -