Solid solution of YBaCu[sub x]Co[sub 2[minus]x]O[sub 5] (0 [le] x [le] 1) and its intergrowth with YBa[sub 2]Cu[sub 3]O[sub 7]

Journal Article · Fri Apr 01 04:00:00 EST 1994 · Chemistry of Materials; (United States)

DOI:https://doi.org/10.1021/cm00040a018· OSTI ID:7268437

Zhou, W ^[1]

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1. Univ. of Cambridge (United Kingdom)

Solid-solution materials of YBaCu[sub x]Co[sub 2[minus]x]O[sub 5] (0 [le] x [le] 1) have been synthesized by solid-state reaction. Using the X-ray diffraction and high resolution electron microscopy techniques, their structures were determined to be related to the defect perovskite structure and have tetragonal unit cells with a [approximately] 3.88 and c [approximately] 7.75 [angstrom]. Annealing YBaCo[sub 2]O[sub 5] in pure oxygen leads to a 3 [times] 3 [times] 1 tetragonal superstructure which can be eliminated by electron beam irradiation or by annealing the specimen in argon, implying the existence of excess oxygen in the yttrium layer. A model for this superstructure with a composition of Y[sub 9]Ba[sub 9]Co[sub 18]O[sub 49] has been suggested and supported by computer simulations of the HREM images. Irregular intergrowth of YBaCo[sub 2]O[sub 5] and YBa[sub 2]Cu[sub 3]O[sub 7] has also been observed from a specimen with a nominal composition of Y[sub 2]Ba[sub 3]Cu[sub 3]Co[sub 2]O[sub 12]. 10 refs., 7 figs., 2 tabs.

• OSTI ID: 7268437
• Journal Information: Chemistry of Materials; (United States), Journal Name: Chemistry of Materials; (United States) Vol. 6:4; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

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