Single-crystal growth and small anisotropy of the lower critical field in oxypnictides: NdFeAsO1 − xFx
- High-quality single crystals of the unconventional superconductor NdFeAsO1 − xFx were grown. We developed a new optimized flux technique to overcome the difficulties in single-crystal growth and the sample quality limitations of NdFeAsO1 − xFx. The normal state of the F-doped samples exhibits simple metallic behavior upon cooling down from room temperature, followed by a sharp superconducting transition. The values of residual resistivity ratio (RRR) is 3.2, 6.4, and 10.3 for x = 0.1, 0.15, and 0.2, respectively. Both the large RRR and the narrow superconducting transition signpost the high quality of the crystals. We have examined the in- and out-of-plane lower critical fields, and the field at which vortices penetrate the sample of NdFeAsO1 − xFx (x = 0.1). The anisotropy ratio [γHc1 (0)] increased slightly with increasing temperature from 0.8 Tc to Tc. The temperature dependence of the first vortex penetration field was obtained under the static magnetic field, H, parallel to the c- and ab- axis, and pronounced changes in the Hc1(T) curvature were observed, which are attributed to the multi-band superconductivity.
Author: | Abanoub R. N. Hanna, Mahmoud Abdel-Hafiez |
---|---|
URN: | urn:nbn:de:hebis:30:3-547925 |
DOI: | https://doi.org/10.3390/cryst10050362 |
ISSN: | 2073-4352 |
Parent Title (English): | Crystals |
Publisher: | MDPI |
Place of publication: | Basel |
Document Type: | Article |
Language: | English |
Date of Publication (online): | 2020/05/01 |
Date of first Publication: | 2020/05/01 |
Publishing Institution: | Universitätsbibliothek Johann Christian Senckenberg |
Release Date: | 2020/05/16 |
Tag: | crystal growth; lower critical field; unconventional superconductor |
Volume: | 10 |
Issue: | 362 |
Page Number: | 8 |
HeBIS-PPN: | 465943144 |
Institutes: | Physik / Physik |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik |
Sammlungen: | Universitätspublikationen |
Licence (German): | Creative Commons - Namensnennung 4.0 |