Transition-metal redistribution in GdBa sub 2 Cu sub 3 minus x M x O sub 7 minus. delta. and YBa sub 2 Cu sub 3 minus x M x O sub 7 minus. delta. ( M =Fe, Co, and Ni): Evidence for Gd-Fe(2) magnetic interactions

Journal Article · Wed Jul 01 00:00:00 EDT 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.46.448· OSTI ID:5000249

Prasanna, T R.S.; Chatterjee, R; O'Handley, R C; Kalonji, G ^[1]

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1. Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

{ital G}dBa{sub 2}Cu{sub 3{minus}{ital x}}O{sub 7{minus}{delta}} and YBa{sub 2}Cu{sub 3{minus}{ital x}}M{sub {ital x}}O{sub 7{minus}{delta}} ({ital M}=Fe, Co, and Ni) high-{ital T}{sub {ital c}} superconductors were prepared by conventional ceramic-processing techniques and characterized by measuring the critical temperature as a function of later quenching from various temperatures. For the Fe-substituted compositions, the {ital T}{sub {ital c}} for the Y-based samples increase while the {ital T}{sub {ital c}} for the Gd-based samples decrease with increasing quench temperatures. Assuming that quenching from elevated temperatures retains the atomic configurations stable at high temperatures, a possible interpretation of these data can be made in terms of a redistribution of Fe from the equilibrium preferred Cu(1) chain sites to the Cu(2) plane sites. A comparison of the data for the Y- and Gd-based superconductors suggests local magnetic interactions between Gd and Fe(2) ions. The data are consistent with superconductivity localized in the Cu-O planes. Gd-based, Co-substituted compositions exhibit behavior similar to Fe-substituted compositions upon quenching treatment. Analysis of Gd-based, Ni-substituted data suggests that two independent processes---thermal disorder and loss of oxygen from the unit cell---operate at high temperatures and determine the final transition-metal distribution. With two independent processes operating at high temperatures, an intrinsic difficulty in determining the transition-metal site-preference energies in the high-{ital T}{sub {ital c}} superconductors is indicated.

• DOE Contract Number: FG02-84ER45174
• OSTI ID: 5000249
• Journal Information: Physical Review, B: Condensed Matter; (United States), Vol. 46:1; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
MAGNETIC PROPERTIES
COPPER OXIDES
YTTRIUM OXIDES
COBALT
GADOLINIUM
HIGH-TC SUPERCONDUCTORS
NICKEL
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
ELEMENTS
METALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RARE EARTHS
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENTS
YTTRIUM COMPOUNDS
360207* - Ceramics
Cermets
& Refractories- Superconducting Properties- (1992-)