Crystal structure and phase transition of PbBaSrYCu3Oy(y=7∼8.4

High-Tcsuperconductivity in three-fluorite-layer copper oxides. I.(Hg,W)Watanabe1, Karppinen2, Motohashi3 et al. 2004Phys. Rev. B4110View full textAdd to dashboardCite

“…In the known phases of category B, m varies from 0 up to 3, whereas s can be increased even up to 7 or 8 (though single-phase bulk samples have been realized only up to s =3). [6][7][8] Phases with s ജ 3 are rather rare and none of them has been "superconductorized" yet. 9 At the same time, no definite explanation has been given why these phases do not show superconductivity.…”

High-resolution electron microscopy and electron diffraction of perovskite-type superconducting copper oxides

“…The indicated atomic arrangements were proposed from the structure image, X-ray diffraction, and energy-dispersive spectroscopy (EDS) analysis. In Figure 11C, zigzag arrays consisting of larger black spots correspond to (Pb, Cu) layers, and on both sides of the (Pb, Cu) layers, there are layers of a mixture of Ba and Sr atoms [43]. In this image, Cu and Y atoms, with smaller atomic numbers, are represented as small dark spots.…”

“…Electron probe microanalysis and iodide titration method are used for quantitative analysis of the element. Figure 11A and B are high-resolution structure images of PbBaSrYCu 3 O 7 [43] and Pb 2 Sr 2 Y 0.5 Ca 0.5 Cu 3 O 8 taken with the incident beam parallel to the a-axis. The PbBaSrYCu 3 O 7 shows superconductivity at 65 K by Ca substitution for Y sites [44], and the Pb 2 Sr 2 YCu 3 O 8 also showed superconductivity at 75 K by Ca substitution for Y sites [46].…”

“…of crystal structures of PbBaSr(Y,Ca)Cu 3 O y (y = 7-8.4) and Pb 2 (Ba,Sr) 2 (Ln,Ce) 2 Cu 3 O y (Ln: Lanthanoid, y = 9-10.4) [43][44][45] were determined by high-resolution electron microscopy, with the aid of electron and X-ray diffraction, and quantitative analysis of compositions of cations and oxygen. Some results of the determination of crystal structures are shown here.…”

Operator-method investigation of the effectiveness of adaptive mirrors

“…It was subsequently reported that the oxygen content for this phase could readily be varied from 7 to 8.4 [15,16] and although non-superconducting in the undoped form, superconductivity was observed when the reduced phase was doped with 30% Ca on the Y sites, with T c ∼65 K [17]. As shown in figure 1, the structure of PbBaSrYCu 3 O 7 contains corner sharing CuO 5 pyramids forming two-dimensional CuO 2 layers, between which the Y 3+ ions are accommodated as in the structures of YBa 2 Cu 3 O 7−δ and Pb 2 Sr 2 Y 1−x Ca x Cu 3 O 8+δ [18].…”