Estimation of AC losses of polycrystalline YBCO by two different methods

Author

Ishii, H. ; Hirano, S. ; Hara, T. ; Yamamoto, T.

Author_Institution

Tokyo Electr. Power Co., Japan

Volume

3

Issue

1

fYear

1993

fDate

3/1/1993 12:00:00 AM

Firstpage

1417

Lastpage

1420

Abstract

AC losses of polycrystalline YBa/sub 2/Cu/sub 3/O/sub y/ were evaluated using AC transport and magnetization techniques. As alternating currents were passed through a cylindrically sintered specimen, effectively resistive voltages were detected by means of a lock-in amplifier and were shown to be linked with AC losses of the specimen. The field dependence of magnetically estimated AC losses for a small chip, synthesized in the same manner, exhibited a plateau region beginning at several tens of oersteds. This field was found to be equal to the self-induced magnetic field created by the DC critical current of the cylindrical specimen and could be attributed to the grain decoupling field. Below this field, the two methods provided almost equivalent AC losses, which also semiquantitatively agreed with theoretical estimation using C.P. Bean´s (1962) critical state model.<>

Keywords

barium compounds; high-temperature superconductors; losses; magnetisation; yttrium compounds; AC losses; AC transport; DC critical current; YBa/sub 2/Cu/sub 3/O/sub y/; critical state model; cylindrically sintered specimen; field dependence; grain decoupling field; magnetization; polycrystalline; self-induced magnetic field; Current measurement; Electric variables measurement; Loss measurement; Magnetic field measurement; Magnetic materials; Magnetization; Superconducting materials; Superconductivity; Voltage; Yttrium barium copper oxide;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.233632

Filename

233632