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Research on high Tc superconducting compoundsMossbauer research using the 21.54 kev resonance radiation of Eu-151 on the high temperature superconductors Bi(2)Ca(0.5)Eu(0.5)Sr(2)CU2O(x), and EuBa(2)CU(3)O(7-x) is performed. For the Bismuth compound the Mossbauer measurements gave a weak signal at room temperature but improved at lower temperatures. Experimental data indicated that europium is located at only one crystallographic site. Isomer shift measurements were .69 + 0.02 mm/s with respect to EuF(3). The linewidth at room temperature was found to be 2.54 mm/s. This value falls within the values observed by other researchers on Eu based 1,2,3 high-Tc compounds. Our results also show the Eu to be trivalent with no trace of divalent europium present. Superconducting europium based 1,2,3 compounds were prepared and measurements completed. Our results show the Eu to be trivalent with no trace of divalent europium present. These compounds had an average isomer shift of .73 mm/s +/- O.02 for all samples made. One of these was irradiated with 3.5 X 10(exp 16) neutrons and a comparison made of the Mossbauer parameters for the irradiated and non-irradiated samples. Experimental results showed no difference between linewidths but a measurable effect was seen for the isomer shift.
Document ID
19960038728
Acquisition Source
Goddard Space Flight Center
Document Type
Contractor Report (CR)
Authors
Oliver, Frederick W.
(Morgan State Univ. Baltimore, MD United States)
Date Acquired
September 6, 2013
Publication Date
June 1, 1996
Subject Category
Electronics And Electrical Engineering
Report/Patent Number
NASA-CR-201114
NAS 1.26:201114
Report Number: NASA-CR-201114
Report Number: NAS 1.26:201114
Accession Number
96N30998
Funding Number(s)
CONTRACT_GRANT: NAG5-2375
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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