Abstract
On oxygen annealing, Pb and Cu atoms in block layers become disordered much more readily in PbBaSrYCu3O7+z than in Pb2Sr2YCu3O8+z. In this work, the structural properties of PbBaSr(Y1-xCax)Cu3O7+z (x=0.2; z=0.0 and 1.35) were studied by X-ray and time-of-flight neutron powder diffraction and compared with those of Pb2Sr2(Y1-xCax)Cu3O8+z. In the superconductor (Tc=39 K) with z=0.0, Pb and Cu atoms in PbO-Cu block layers are perfectly ordered, in agreement with structural data reported by Rouillon et al. On the other hand, oxygen atoms are incorporated in the Cu layer in the oxygen-annealed sample with z=1.35, which gives rise to a disordered arrangement of Pb and Cu atoms in the block layers. Bond-valence-sum calculations show that the oxidation states of the Pb and Cu atoms respectively change from +2 to ca. +4 and from +1 to ca. +2 upon oxygen incorporation. The effects of lone electron pairs at Pb2+ ions and the structure of the block layer on metal disordering is discussed in connection with the difference in oxidation behavior between PbBaSr(Y1-xCax)Cu3O7+z and Pb2Sr2(Y1-xCax)Cu3O8+z.
| Original language | English |
|---|---|
| Pages (from-to) | 357-366 |
| Number of pages | 10 |
| Journal | Physica C: Superconductivity and its Applications |
| Volume | 231 |
| Issue number | 3-4 |
| DOIs | |
| Publication status | Published - 1994 Oct 1 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Condensed Matter Physics
Cite this
Structural changes of PbBaSr(Y0.8Ca0.2)Cu3O7+z on oxygen introduction into block layers. / Ishigaki, T.; Yamamoto, Ayako; Izumi, F.; Kamiyama, T.; Asano, H.; Syono, Y.
In: Physica C: Superconductivity and its Applications, Vol. 231, No. 3-4, 01.10.1994, p. 357-366.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Structural changes of PbBaSr(Y0.8Ca0.2)Cu3O7+z on oxygen introduction into block layers
AU - Ishigaki, T.
AU - Yamamoto, Ayako
AU - Izumi, F.
AU - Kamiyama, T.
AU - Asano, H.
AU - Syono, Y.
PY - 1994/10/1
Y1 - 1994/10/1
N2 - On oxygen annealing, Pb and Cu atoms in block layers become disordered much more readily in PbBaSrYCu3O7+z than in Pb2Sr2YCu3O8+z. In this work, the structural properties of PbBaSr(Y1-xCax)Cu3O7+z (x=0.2; z=0.0 and 1.35) were studied by X-ray and time-of-flight neutron powder diffraction and compared with those of Pb2Sr2(Y1-xCax)Cu3O8+z. In the superconductor (Tc=39 K) with z=0.0, Pb and Cu atoms in PbO-Cu block layers are perfectly ordered, in agreement with structural data reported by Rouillon et al. On the other hand, oxygen atoms are incorporated in the Cu layer in the oxygen-annealed sample with z=1.35, which gives rise to a disordered arrangement of Pb and Cu atoms in the block layers. Bond-valence-sum calculations show that the oxidation states of the Pb and Cu atoms respectively change from +2 to ca. +4 and from +1 to ca. +2 upon oxygen incorporation. The effects of lone electron pairs at Pb2+ ions and the structure of the block layer on metal disordering is discussed in connection with the difference in oxidation behavior between PbBaSr(Y1-xCax)Cu3O7+z and Pb2Sr2(Y1-xCax)Cu3O8+z.
AB - On oxygen annealing, Pb and Cu atoms in block layers become disordered much more readily in PbBaSrYCu3O7+z than in Pb2Sr2YCu3O8+z. In this work, the structural properties of PbBaSr(Y1-xCax)Cu3O7+z (x=0.2; z=0.0 and 1.35) were studied by X-ray and time-of-flight neutron powder diffraction and compared with those of Pb2Sr2(Y1-xCax)Cu3O8+z. In the superconductor (Tc=39 K) with z=0.0, Pb and Cu atoms in PbO-Cu block layers are perfectly ordered, in agreement with structural data reported by Rouillon et al. On the other hand, oxygen atoms are incorporated in the Cu layer in the oxygen-annealed sample with z=1.35, which gives rise to a disordered arrangement of Pb and Cu atoms in the block layers. Bond-valence-sum calculations show that the oxidation states of the Pb and Cu atoms respectively change from +2 to ca. +4 and from +1 to ca. +2 upon oxygen incorporation. The effects of lone electron pairs at Pb2+ ions and the structure of the block layer on metal disordering is discussed in connection with the difference in oxidation behavior between PbBaSr(Y1-xCax)Cu3O7+z and Pb2Sr2(Y1-xCax)Cu3O8+z.
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U2 - 10.1016/0921-4534(94)90645-9
DO - 10.1016/0921-4534(94)90645-9
M3 - Article
VL - 231
SP - 357
EP - 366
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
SN - 0921-4534
IS - 3-4
ER -