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Stability of bulk Ba2YCu3O(7-x) in a variety of environmentsSmall bars of ceramic Ba2YCu3O(7-x) were fabricated and subjected to environments similar to those that might be encountered during some NASA missions. These conditions include ambient conditions, high humidity, vacuum, and high fluences of electrons and protrons. The normal state resistivity or critical current density (J sub c) were monitored during these tests to assess the stability of the material. When normal state resistivity is used as a criterion, the ambient stability of these samples was relatively good, exhibiting only a 2 percent degradation over a 3 month period. The humidity stability was shown to be very poor, and to be a steep function of temperature. Samples stored at 50 C for 40 min increased in normal state resistivity by four orders of magnitude. Kinetic analysis indicates that the degradation reaction is second order with water vapor concentration. It is suspected that humidity degradation also accounts for the ambient instability. The samples were stable to vacuum over a period of at least 3 months. Degradation of J sub c in a 1 MeV electron fluence of 9.7 x 10 to the 14th e(-)/sq cm was determined to be no more than about 2 percent. Degradation of J sub c in a 8.7 x 10 to the 14th p(+)/sq cm of 42 MeV protons was found to be grain size dependent. Samples with smaller grain size and initial J sub c of about 240 A/sq cm showed no degradation. while that with larger grain size and an initial J sub c of about 30 A/sq cm degraded to 37 percent of its original value.
Document ID
19890004939
Document Type
Technical Memorandum (TM)
Authors
Gaier, James R. (NASA Lewis Research Center Cleveland, OH., United States)
Hepp, Aloysius F. (NASA Lewis Research Center Cleveland, OH., United States)
Curtis, Henry B. (NASA Lewis Research Center Cleveland, OH., United States)
Schupp, Donald A. (Rensselaer Polytechnic Inst. Troy, NY., United States)
Hambourger, Paul D. (Cleveland State Univ. OH., United States)
Blue, James W. (Cleveland Clinic Foundation OH., United States)
Date Acquired
September 5, 2013
Publication Date
December 1, 1988
Subject Category
NONMETALLIC MATERIALS
Report/Patent Number
NASA-TM-101401
E-4485
NAS 1.15:101401
Meeting Information
Fall Meeting of the Materials Research Society(Boston, MA)
Funding Number(s)
PROJECT: RTOP 506-41-41
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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