Bending strain study of Bi-2223/Ag tapes using Hall sensor magnetometry

Author

Lahtinen, Markku ; Paasi, Jaakko ; Sarkaniemi, Jyrki ; Han, Zhenghe ; Freltoft, Torsten

Author_Institution

Lab. of Electr. & Magnetism, Tampere Univ. of Technol., Finland

Volume

32

Issue

4

fYear

1996

fDate

7/1/1996 12:00:00 AM

Firstpage

2814

Lastpage

2817

Abstract

The influence of room temperature bending on critical current (I _c) of Bi-2223/Ag tapes is studied by Hall sensor magnetometry, four-point method and scanning electron microscopy. Hall sensor magnetometry allows us to assess tape homogeneity and the amount of mechanical damage caused by bending. The microstructure of the Bi-2223 ceramic is found to strongly affect the tape behavior under bending strain. In a tape with moderate I_c=6.1 A at 77 K and a porous ceramic core, crack propagation took place normal to the Ag-ceramic interface, whereas in tapes with dense core, I_c above 10 A at 77 K, cracks propagated in the tape plane. In monofilamentary tapes core homogeneity correlated with good bending strain performance. In multifilamentary tapes crack propagation between filaments was prohibited by the Ag matrix, thus leading to enhanced strain tolerance. In the high I_c tapes studied, bending to 25 mm radius resulted in 1%-2% I_c degradation

Keywords

bending; bismuth compounds; calcium compounds; critical current density (superconductivity); high-temperature superconductors; magnetic field measurement; multifilamentary superconductors; scanning electron microscopy; silver; strain measurement; strontium compounds; 10 A; 77 K; Bi-2223/Ag tapes; Bi₂Sr₂Ca₂Cu₃O₁₀-Ag; Hall sensor magnetometry; bending strain; crack propagation; critical current; four-point method; high temperature superconductor; mechanical damage; microstructure; monofilamentary tapes; multifilamentary tapes; porous ceramic core; room temperature bending; scanning electron microscopy; strain tolerance; tape homogeneity; Capacitive sensors; Ceramics; Critical current; Magnetic field induced strain; Magnetic force microscopy; Magnetic sensors; Mechanical sensors; Microstructure; Scanning electron microscopy; Temperature sensors;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.511460

Filename

511460