Abstract
We have performed magnetic measurements in two melt-textured NdBa2Cu3O7-δ samples with Nd422 inclusions under magnetic fields from 0.05 up to 14 T, applied parallel to the ab planes. The measurements were made with a superconducting quantum interference device (SQUID) and a vibrating sample magnetometer (VSM). Paramagnetic moments could be observed during FCC (field-cooled cooling) and FCW (field-cooled warming) experiments. This effect, known as Paramagnetic Meissner Effect (PME), persisted up to 14 T and strong irreversibilities were observed among FCC and FCW experiments, revealing the presence of time effects. These time effects were confirmed by specific magnetic relaxation experiments in different cooling rates and temperatures, showing an anomalous and curious paramagnetic behavior. We explain our results based on the flux-compressed state generated within nonsuperconducting regions of the sample, such as the Nd422 inclusions dispersed into the superconducting matrix. These inclusions may produce a strong vortex pinning that stabilize the paramagnetic state, allowing the admission of extra vortices into the sample responsible for the positive moments during the relaxation experiments.
Highlights
The paramagnetic Meissner effect, or PME, has been characterized by a paramagnetic moment exhibited when a superconducting material is cooled below the critical temperature in the presence of a magnetic field, contrary to conventional diamagnetism
In this work we present the experimental observation of the paramagnetic Meissner effect (PME) in melt-textured NdBa2Cu3O7- δ samples in field-cooled (FC) experiments with magnetic fields up to 14 T applied along the ab planes
Our results show a PME with a time dependence confirmed by specific magnetic relaxation experiments
Summary
The paramagnetic Meissner effect, or PME, has been characterized by a paramagnetic moment exhibited when a superconducting material is cooled below the critical temperature in the presence of a magnetic field (field-cooled procedure), contrary to conventional diamagnetism. Some models attribute the origin of the PME as a consequence of π junctions randomly distributed in a granular array of superconducting grains [18,19,20,21], or a compressed flux state modulated by pinning effects [22,23,24]. In this work we present the experimental observation of the paramagnetic Meissner effect (PME) in melt-textured NdBa2Cu3O7- δ samples in field-cooled (FC) experiments with magnetic fields up to 14 T applied along the ab planes.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
