Abstract
YBa2Cu3O7-δfilms grown on both SrTiO3single-crystal and rolling-assisted biaxially textured (Ni) substrates (RABiTS) carry high critical current densities Jc. A geometrical barrier to vortex motion raises the apparent Jc, but also increases power loss associated with ac transport current through such tape above that expected from Norris’s 1970 theory of hysteretic energy loss. Present theoretical estimates of the geometrical barrier have insufficient magnitude to account for our observations at low ac current levels. Evidence is reported that the ferromagnetic Ni substrate makes no significant contribution to the tape self-field loss. Loss is enhanced, and Jcmodestly reduced by the presence of low-angle grain boundaries. Application of dc magnetic field further lowers Jcand raises loss in films.
Original language | English |
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Pages (from-to) | 6878-6883 |
Number of pages | 6 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 60 |
Issue number | 9 |
DOIs | |
State | Published - 1999 |