The relationship of structure to superconductivity in the Pr-Ba-Cu-O system

Thesis/Dissertation · Tue May 10 00:00:00 EDT 1994

DOI:https://doi.org/10.2172/10161809· OSTI ID:10161809

Minseo, Park ^[1]

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1. Iowa State Univ., Ames, IA (United States)

The relation of structure to lack of superconductivity in Pr-Ba-Cu-O was systematically investigated. First, the phase equilibria of this system was studied to find the processing parameters which maximize the cation-site ordering between Pr and Ba ions. Second, a comparative study between superconducting Nd-Ba-Cu-0 and non- superconducting Pr-Ba-Cu-0 was performed by forming solid-solution Nd- Pr-Ba-Cu-0. The relation between structure and superconductivity in Ndb_1-xPr_xBa₂Cu₃O_7-δ is investigated. T_c decreases monotonically with increasing x and superconductivity disappears at around x=0.3-0.4. T_c is enhanced by 10K when the sample is processed at an oxygen partial pressure (PO₂) of 0.01 atm, followed by oxygenation at 450C. Depression of (T_c) as a function of x and PO ₂ is explained in terms of a charge-transfer model. It is suggested that destruction of superconductivity in the RE_1-xPr_xBa₂CU₃O_7-δ (RE=rare-earth) system can be viewed as disruption of four-fold planar coordinated Cu ions in the chain-site due to permanent occupation of extra Pr ions on Ba sites.

• Research Organization: Ames Lab., Ames, IA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 10161809
• Report Number(s): IS-T-1707; ON: DE94014231
• Resource Relation: Other Information: TH: Thesis (M.S.); PBD: 10 May 1994
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
HIGH-TC SUPERCONDUCTORS
PHASE STUDIES
SUPERCONDUCTIVITY
PRASEODYMIUM OXIDES
BARIUM OXIDES
COPPER OXIDES
NEODYMIUM OXIDES
TRANSITION TEMPERATURE
CORRELATIONS
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