TY - JOUR
T1 - Effect of Tl doping on the phase stability of Hg2Ba2(Y,Ca)1Cu2O 8-δ superconductors prepared by a high-pressure technique
AU - Tokiwa-Yamamoto, Ayako
AU - Tatsuki, Tadashi
AU - Wu, Xiao Jing
AU - Adachi, Seiji
AU - Tanabe, Keiichi
N1 - Funding Information:
The authors thank A. Fukuoka for useful discussion. This work was supported by NEDO for the R&D of Industrial Science and Technology Frontier Program.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 1996/3/1
Y1 - 1996/3/1
N2 - (Hg, T1) based cuprates with the nominal compositions of (Hg1-xT1x)2Ba2Y1-yCa yCu2O8-δ (0 ≦ x ≦ 1.0 and 0 ≦ y ≦ 1.0) were prepared under a high pressure and high temperature. The solubility of Ca ions into Ae Hg-2212 phase for various T1 contents was examined by X-ray powder diffraction and energy-dispersive X-ray spectroscopy. The substitution of Ca2+ for the Y3+ site for the samples with x = 0.3 and 0.5 is realized over a full range of 0 ≦ y ≦ 1.0, while the solubility range is limited for the samples with x ≦ 0.15 and x ≧ 0.75. The samples with x = 0.3 exhibited a maximum Tc of 84 K, which was about 30 K higher than the maximum Tc for the samples with x = 0. The significant extension of Ca solubility for the T1 doped samples is probably explained by the compensation of excess negative charges in the (Hg1-xT1x)2O2-δ charge reservoir. The fact that the Y free Hg-2212 phase is obtained by T1 doping suggests the possibility of synthesizing a Hg-22(n - 1)n (n = 3, 4, ⋯) homologous series.
AB - (Hg, T1) based cuprates with the nominal compositions of (Hg1-xT1x)2Ba2Y1-yCa yCu2O8-δ (0 ≦ x ≦ 1.0 and 0 ≦ y ≦ 1.0) were prepared under a high pressure and high temperature. The solubility of Ca ions into Ae Hg-2212 phase for various T1 contents was examined by X-ray powder diffraction and energy-dispersive X-ray spectroscopy. The substitution of Ca2+ for the Y3+ site for the samples with x = 0.3 and 0.5 is realized over a full range of 0 ≦ y ≦ 1.0, while the solubility range is limited for the samples with x ≦ 0.15 and x ≧ 0.75. The samples with x = 0.3 exhibited a maximum Tc of 84 K, which was about 30 K higher than the maximum Tc for the samples with x = 0. The significant extension of Ca solubility for the T1 doped samples is probably explained by the compensation of excess negative charges in the (Hg1-xT1x)2O2-δ charge reservoir. The fact that the Y free Hg-2212 phase is obtained by T1 doping suggests the possibility of synthesizing a Hg-22(n - 1)n (n = 3, 4, ⋯) homologous series.
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U2 - 10.1016/0921-4534(96)00064-0
DO - 10.1016/0921-4534(96)00064-0
M3 - Article
AN - SCOPUS:0030110276
SN - 0921-4534
VL - 259
SP - 36
EP - 42
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
IS - 1-2
ER -