Transverse compressive stress, fatigue, and magnetic substrate effects on the critical current density of Y-Ba-Cu-O coated RABiTS tapes

Published

January 1, 2002

Author(s)

Najib Cheggour, John (Jack) W. Ekin, Cameron C. Clickner, Ron Feenstra, P Goyal, D F. Paranthaman, D F. Lee, D M. Kroeger, D. K. Christen

Abstract

The electromechanical properties of (0.3 υm thick) yttrium-barium-copper-oxide (YBCO) coatings on buffered pure-nickel rolling-assisted-biaxially-textured substrates (RABiTS) were measured at 76 K and self magnetic field. YBCO coatings on buffered substrates both 50 υm 125 υm thick were tested. Significant degradation of transport critical-current density (J_c) can occur from transverse compressive stress unless the inplane yielding of the substrate is prevented by providing friction support to the sample or by using substrate materials of high yield-strength. Scanning electron microscopy was used to investigate the microstructure of the samples after electromechanical testing. Isolated defective regions were found with a mixed pattern of cracks, both longitudinal and transverse to the direction of electrical-current flow. the more the degradation of (J_c) from electromechanical testing, the greater the density of the observed cracked regions. Also, it was found that the use of magnetic substrates in the fabrication of the YBCO coated-conductor tapes produces a significant reduction in (J_c) when the tapes are arranged in a stack of two or more layers. This effect is reversible upon unstacking the tapes.

Citation

Advances in Cryogenic Engineering

Volume

48

Pub Type

Journals

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Keywords

critical current density, fatigue, high Tc superconductors, transverse compressive stress, YBaCuI, yield strength

Citation

Cheggour, N. , W., J. , Clickner, C. , Feenstra, R. , Goyal, P. , Paranthaman, D. , Lee, D. , Kroeger, D. and Christen, D. (2002), Transverse compressive stress, fatigue, and magnetic substrate effects on the critical current density of Y-Ba-Cu-O coated RABiTS tapes, Advances in Cryogenic Engineering, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=30816 (Accessed November 21, 2024)