TY - JOUR
T1 - Magnetization relaxation in superconducting YBa2Cu3O7 films with embedded nanorods and nanoparticles
AU - Miu, L.
AU - Mele, P.
AU - Ivan, I.
AU - Ionescu, A. M.
AU - Crisan, A.
AU - Badica, P.
AU - Miu, D.
N1 - Funding Information:
Research supported by UEFISCDI, Romania, under Grant PN II PCCA Nr. 138/2012, and 7/2012. All the authors contributed equally to this work. The kind assistance of the Alexander von Humboldt Foundation is gratefully acknowledged.
Publisher Copyright:
© Springer-Verlag Berlin Heidelberg 2014.
PY - 2014
Y1 - 2014
N2 - Vortex pinning on natural and artificial defects is essential for large scale applications of superconducting materials. One of the most promising solutions for the creation of efficient pinning structures is to combine the strong pinning supplied by columnar defects (with the radius of the order of the superconducting coherence length) and the presence of random quenched disorder, which inhibits the detrimental vortex kink formation. A strong pinning is revealed by high values of the vortex activation energy in the magnetic relaxation process. We present a critical analysis of the interpretation of the relaxation data at long- and short time scales, by extracting the so called normalized vortex-creep activation energy. This allowed us to find the actual temperature interval for the characteristic vortex excitations in YBa2Cu3O7 films with embedded BaZrO3 nanorods (preferentially oriented along the c axis), and to unambiguously determine the characteristic vortex pinning energy. The observed drastic change of magnetic relaxation at short time scales (attained in standard AC measurements) is attributed to a large contribution of the pinning enhanced viscosity to the vortex hopping activation energy.
AB - Vortex pinning on natural and artificial defects is essential for large scale applications of superconducting materials. One of the most promising solutions for the creation of efficient pinning structures is to combine the strong pinning supplied by columnar defects (with the radius of the order of the superconducting coherence length) and the presence of random quenched disorder, which inhibits the detrimental vortex kink formation. A strong pinning is revealed by high values of the vortex activation energy in the magnetic relaxation process. We present a critical analysis of the interpretation of the relaxation data at long- and short time scales, by extracting the so called normalized vortex-creep activation energy. This allowed us to find the actual temperature interval for the characteristic vortex excitations in YBa2Cu3O7 films with embedded BaZrO3 nanorods (preferentially oriented along the c axis), and to unambiguously determine the characteristic vortex pinning energy. The observed drastic change of magnetic relaxation at short time scales (attained in standard AC measurements) is attributed to a large contribution of the pinning enhanced viscosity to the vortex hopping activation energy.
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U2 - 10.1007/978-3-662-44479-5_9
DO - 10.1007/978-3-662-44479-5_9
M3 - Article
AN - SCOPUS:84921644547
VL - 205
SP - 293
EP - 317
JO - Springer Series in Materials Science
JF - Springer Series in Materials Science
SN - 0933-033X
ER -