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Studies of iron impurities in YxPr1-xBa2Cu3O7-deltaPr is the only rare earth which, when substituted for Y in YBa2Cu3O7, significantly alters the superconducting transition temperature T(sub c) without changing the crystal structure. For YxPr1-xBa2Cu3O7-delta with delta approx. equal to 0, T(sub c) is reduced rapidly as x is increased, reaching zero for x about 0.5. For x above 0.5 the compound is antiferromagnetic with a Neel temperature that increases with increasing x, rising to above room temperature for x near 1. A similar behavior is observed when the oxygen deficit delta is increased from zero to 1 with x=0. For the case of Pr substitution, the drop in T(sub c) is believed due to magnetic interactions. For the case of varying delta with x=0, the drop can be attributed to a combination of magnetic interactions, band filling, and changes in crystal structure. To study these effects, the Mossbauer effect of 57 Fe atoms substituted for the Cu atoms has been observed as a function of delta, x, and temperature. The observed spectra are all well described by a two quadrupole-split pairs, a central singlet, and a six-line magnetic hyperfine field pattern. For several Pr compositions both delta and temperature were varied, and the results support the hypothesis that a magnetic interaction exists between the Fe in the Cu lattice and the substitutional Pr atoms.
Document ID
19900018549
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Swartzendruber, L. J. (National Inst. of Standards and Technology Gaithersburg, MD., United States)
Bennett, L. H. (National Inst. of Standards and Technology Gaithersburg, MD., United States)
Ritter, J. (National Inst. of Standards and Technology Gaithersburg, MD., United States)
Rubinstein, M. (Naval Research Lab. Washington, DC., United States)
Harford, M. Z. (Naval Research Lab. Washington, DC., United States)
Date Acquired
September 6, 2013
Publication Date
April 1, 1990
Publication Information
Publication: NASA, Goddard Space Flight Center, AMSAHTS 1990: Advances in Materials Science and Applications of High Temperature Superconductors
Subject Category
Solid-State Physics
Accession Number
90N27865
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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