Abstract
Two interesting topics of layered high-Tc copper oxides, Tl and Pb systems investigated recently in our laboratory are presented to get better understanding of the chemistry and superconductivity of these peculiar compounds. First, a comparative study of double and single Tl layer oxides has been done. The most probable explanation for the origin of holes responsible for a high Tc above 100 K in the double Tl layer oxides is electron transfer mechanism Tl3-t-Cu2+2t/n. Evidence for a reduced state in Tl ions is obtained by XPS and XANES measurements. Single Tl layer oxides are shown to be more ionic by XPS and NMR measurements. The block layer of Pb(Ba,Sr)2YCu3O7 lacks one PbO layer from the PbO-Cu-PbO block layer as revealed by high-resolution electron microscopy. In the (Pb,Cu) double layer oxides, an abrupt oxygen removal and uptake accompanied by phase transition was observed to occur in a reversible fashion. Pb(Ba,Sr)2YCu3O7 became a 60 K superconductor by partial substitution of Y with Ca.
| Original language | English |
|---|---|
| Pages (from-to) | 9-13 |
| Number of pages | 5 |
| Journal | Physica C: Superconductivity and its Applications |
| Volume | 190 |
| Issue number | 1-2 |
| DOIs | |
| Publication status | Published - 1991 Dec 2 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering
Cite this
Chemistry of superconducting Cu oxides with the block layers consisting of Tl, Pb and Bi ions. / Syono, Yasuhiko; Kikuchi, Masae; Nakajima, Satoru; Yamamoto, Ayako.
In: Physica C: Superconductivity and its Applications, Vol. 190, No. 1-2, 02.12.1991, p. 9-13.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Chemistry of superconducting Cu oxides with the block layers consisting of Tl, Pb and Bi ions
AU - Syono, Yasuhiko
AU - Kikuchi, Masae
AU - Nakajima, Satoru
AU - Yamamoto, Ayako
PY - 1991/12/2
Y1 - 1991/12/2
N2 - Two interesting topics of layered high-Tc copper oxides, Tl and Pb systems investigated recently in our laboratory are presented to get better understanding of the chemistry and superconductivity of these peculiar compounds. First, a comparative study of double and single Tl layer oxides has been done. The most probable explanation for the origin of holes responsible for a high Tc above 100 K in the double Tl layer oxides is electron transfer mechanism Tl3-t-Cu2+2t/n. Evidence for a reduced state in Tl ions is obtained by XPS and XANES measurements. Single Tl layer oxides are shown to be more ionic by XPS and NMR measurements. The block layer of Pb(Ba,Sr)2YCu3O7 lacks one PbO layer from the PbO-Cu-PbO block layer as revealed by high-resolution electron microscopy. In the (Pb,Cu) double layer oxides, an abrupt oxygen removal and uptake accompanied by phase transition was observed to occur in a reversible fashion. Pb(Ba,Sr)2YCu3O7 became a 60 K superconductor by partial substitution of Y with Ca.
AB - Two interesting topics of layered high-Tc copper oxides, Tl and Pb systems investigated recently in our laboratory are presented to get better understanding of the chemistry and superconductivity of these peculiar compounds. First, a comparative study of double and single Tl layer oxides has been done. The most probable explanation for the origin of holes responsible for a high Tc above 100 K in the double Tl layer oxides is electron transfer mechanism Tl3-t-Cu2+2t/n. Evidence for a reduced state in Tl ions is obtained by XPS and XANES measurements. Single Tl layer oxides are shown to be more ionic by XPS and NMR measurements. The block layer of Pb(Ba,Sr)2YCu3O7 lacks one PbO layer from the PbO-Cu-PbO block layer as revealed by high-resolution electron microscopy. In the (Pb,Cu) double layer oxides, an abrupt oxygen removal and uptake accompanied by phase transition was observed to occur in a reversible fashion. Pb(Ba,Sr)2YCu3O7 became a 60 K superconductor by partial substitution of Y with Ca.
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U2 - 10.1016/S0921-4534(05)80184-4
DO - 10.1016/S0921-4534(05)80184-4
M3 - Article
AN - SCOPUS:0026414817
VL - 190
SP - 9
EP - 13
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
SN - 0921-4534
IS - 1-2
ER -