Abstract
We report direct evidence of surface barriers in single crystals of Tl2Ba2CuO6 superconductors. Magnetization is measured as a function of temperature with magnetic field applied parallel to the c axis. For small field, a characteristic linear increase in M is observed at an onset temperature T1. For higher magnetic field, a new feature at low T is observed in the M(T) data. The flux penetration temperature is retarded to a higher temperature. The penetration field Hp at temperature below 50 K determined by the first linear rise in M(T) can be fitted with the relation Hp(T)=Hcexp(-T/T0), consistent with a model where two-dimensional pancakes penetrate the Bean-Livingston barrier by thermal activation. The low critical field Hc1 determined from the bulk penetration of vortices is also presented.
Original language | English (US) |
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Pages (from-to) | 5535-5538 |
Number of pages | 4 |
Journal | Physical Review B |
Volume | 47 |
Issue number | 9 |
DOIs | |
State | Published - 1993 |
ASJC Scopus subject areas
- Condensed Matter Physics