Abstract
The magnetization curves of YBa2Cu3O7-' crystals are widely observed to exhibit a pronounced low-field minimum in the temperature range 30 K<T<Tc. We demonstrate that these magnetization anomalies correlate with the c-axis lattice parameter, and hence with the specific oxygen deficiency '. We interpret this low-field feature in terms of a field-induced decoupling of regions of oxygen-rich material by boundaries of oxygen-poor material, a phenomenon reminiscent of the behavior in granular superconductors. A phase diagram that demarcates the multigrain onset as a function of temperature and ' is then constructed. The shape of the phase boundaries is described using a percolation model. This analysis demonstrates that magnetization is a very sensitive measure of crystal quality.
Original language | English (US) |
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Pages (from-to) | 4916-4922 |
Number of pages | 7 |
Journal | Physical Review B |
Volume | 45 |
Issue number | 9 |
DOIs | |
State | Published - Jan 1 1992 |
Externally published | Yes |
ASJC Scopus subject areas
- Condensed Matter Physics