Functional behavior of the melt-textured YBa2Cu3O7-δ Meissner effectanomalous magnetic relaxation observed in samples showing the paramagnetic

Autor: Dias, Fábio Teixeira, Vieira, Valdemar das Neves, Garcia, Evelin da Luz, Wolff-Fabris, Frederik, Kampert, Erik, Gouvêa, Cristol de Paiva, Schaf, Jacob, Obradors, Xavier, Puig Molina, Teresa, Roa Rovira, Joan Josep
Přispěvatelé: Ministério da Ciência, Tecnologia e Inovação (Brasil), Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), Helmholtz-Zentrum Dresden-Rossendorf
Rok vydání: 2016
Předmět:
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
instname
Popis: We have studied the functional behavior of the field-cooled (FC) magnetic relaxation observed in melt-textured YBa2Cu3O7-δ (Y123) samples with 30 wt% of Y2Ba1Cu1O5 (Y211) phase, in order to investigate anomalous paramagnetic moments observed during the experiments. FC magnetic relaxation experiments were performed under controlled conditions, such as cooling rate and temperature. Magnetic fields up to 5T were applied parallel to the ab plane and along the c-axis. Our results are associated with the para-magnetic Meissner effect (PME), characterized by positive moments during FC experiments, and related to the magnetic flux compression into the samples. After different attempts our experimental data could be adequately fitted by an exponential decay function with different relaxation times. We discuss our results suggesting the existence of different and preferential flux dynamics governing the anomalous FC paramagnetic relaxation in different time intervals. This work is one of the first attempts to interpret this controversial effect in a simple analysis of the pinning mechanisms and flux dynamics acting during the time evolution of the magnetic moment. However, the results may be useful to develop models to explain this interesting and still misunderstood feature of the paramagnetic Meissner effect.
This work was financed by the Brazilian MCTI/CNPq Universal 14/2012 (contract number 477506/2012-7). We acknowledge the support of the HLD-HZDR, member of the European Magnetic Field Laboratory (EMFL).
Databáze: OpenAIRE
Externí odkaz: