ISSN:
1573-7357
Keywords:
74.60G
;
74.30C
;
74.72Bk
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Using vector magnetic moment measurements, in twinned YBa2Cu3Oy single crystals we observe a nearly reversible Mab component of the magnetisation with sharp peaks in the dependence of Mab on the magnetic field H and angle ϕ between c-axis and magnetic field. The association of these features with twin boundaries is supported by geometrical arguments and by comparison with detwinned samples. For a crystal with a single dominant direction of twin boundaries, the initial slope of the Mab(H) and Mab(ϕ) dependences corresponds closely to ideal shielding of the transverse H component, as expected for the fully-locked vortex state. The peak position, which is related to the locking angle, shows a close to linear Hp −1 vs ϕ dependence, which corresponds to a fixed value of HL, the locking field. The influence of twins vanishes above a trapping angle ϕT which shows rather weak temperature and magnetic field dependences; at 60K and 1T these parameters are μoHL=27mT and ϕT ≈ 10 °.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00753847
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