Observation of Large Unquantized Magnetic Flux Generated along Asymmetric Tilt Boundary of YBa_2Cu_3Oy LPE Film
Abstract
We have investigated the magnetic flux state of high-Tc films with [001]-tilt grain boundaries by a scanning SQUID microscope. In measurements for a field-cooled 3-μm-thick YBa_2Cu_3Oy liquid-phase-epitaxy (LPE) film with an asymmetric 45^circ grain boundary, unquantized disordered flux was observed along the grain boundary. The maximum flux variation was found to be approximately ±(1/2)Φ_0, which is much larger than that previously reported for PLD films.^( J. Mannhart et al)., Phys. Rev. Lett. 77, 2782 (1996). This disordered flux is probably generated owing to the faceting along the grain boundary and the d-wave order parameter, and it is deduced that the large flux variation is caused by the large facet length of 1-10 μm in our LPE film, which is comparable to the Josephson penetration depth. In addition, it was found that the observed disordered flux was unchanged for elevating the sample temperature up to just below the boundary T_c.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2001
- Bibcode:
- 2001APS..MARE28004S