TY - JOUR
T1 - Determination of the spatial length scale of the magnetic field distribution in YBa2Cu3O7 ceramics and Bi2Sr2CaCu2O8 crystal
AU - Bontemps, N.
AU - Bertin, P. Y.
AU - Davidov, D.
AU - Monod, P.
AU - Lacour, C.
AU - Even, R.
AU - Moshchalkov, V. V.
PY - 1991/12/1
Y1 - 1991/12/1
N2 - We have measured the EPR linewidth of a free radical layer as a function of height (0.28 to 10μm) above the surface of an YBa2Cu3O7 superconducting ceramic. We find characteristic lengthscales of the order of 20-40 μm for the field distribution at the surface. This result rules out the Abrikosov vortex lattice as the main source of surface EPR broadening, which we assign to extrinsic sources such as the grain structure. In contrast, the width of the free radical line, when deposited on the surface of a Bi2Sr2CaCu2O8 single crystal, exhibits a significant broadening only below the temperature where irreversibility sets in.
AB - We have measured the EPR linewidth of a free radical layer as a function of height (0.28 to 10μm) above the surface of an YBa2Cu3O7 superconducting ceramic. We find characteristic lengthscales of the order of 20-40 μm for the field distribution at the surface. This result rules out the Abrikosov vortex lattice as the main source of surface EPR broadening, which we assign to extrinsic sources such as the grain structure. In contrast, the width of the free radical line, when deposited on the surface of a Bi2Sr2CaCu2O8 single crystal, exhibits a significant broadening only below the temperature where irreversibility sets in.
UR - http://www.scopus.com/inward/record.url?scp=0026404201&partnerID=8YFLogxK
U2 - 10.1016/0921-4534(91)91030-8
DO - 10.1016/0921-4534(91)91030-8
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AN - SCOPUS:0026404201
SN - 0921-4534
VL - 185-189
SP - 1809
EP - 1810
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
IS - PART 3
ER -