Intergranular AC loss in high-temperature superconductors

✍ Scribed by K.-H. Müller; A.J. Pauza

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 360 KB
• Volume: 161
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(89)90342-0

✦ Synopsis

The AC loss and the real part of the AC permeability at low frequency and low magnetic field were measured for a sintered polycrystalline Y-Ba-Cu-O sample. The dependence on the AC amplitude and a superimposed DC magnetic field is explained in terms of a critical state model which accounts for the intergranular and intragranular effects. The dependence of the intergranular pinning force density on the local magnetic field is derived from the pinning potential of a Josephson vortex in a granular superconductor. The large AC losses are mainly due to bulk pinning while losses caused by surface barriers to flux entry and exit as well as annihilation losses are negligible.