Journal Article

PreJuSER-15732

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Mixed-state Hall effect and flux pinning in Ba (Fe1-xCox) 2As2 single crystals (x = 0.08 and 0.10)

Wang, L. M. ; Sou, U. C. ; Yang, H. C. ÜFZJ* ; Chang, L. J. ; Cheng, C. M. ; Tsuei, K. D. ; Su, Y.FZJ* ; Wolf, T. ; Adelmann, P.

2011
APS College Park, Md.

This record in other databases:  

Please use a persistent id in citations: http://hdl.handle.net/2128/10933  doi:10.1103/PhysRevB.83.134506

Abstract: Longitudinal and Hall resistivities, scaling behavior, and magnetizations are examined to study the effect of flux pinning in Ba(Fe1-xCox)(2)As-2 (BFCA) single crystals with x = 0.08 and 0.01. Larger values of activation energy, critical current density, and pinning force are obtained in BFCA with x = 0.10, indicating relatively strong pinning. The sign reversal of Hall resistivities is clearly observed in BFCA with x = 0.10. The correlation between longitudinal and Hall resistivities shows the scaling behavior of rho(xy) proportional to (rho(xx))(beta) with exponents beta = 3.0-3.4 and 2.0+/-0.2 for BFCA crystals with x = 0.08 and 0.10, respectively. Furthermore, the normal-state Hall angle is also observed to follow cot theta(H) = Lambda T-2 + C in BFCA crystals, and is explained by the Anderson theory. The relatively large C/Lambda value for BFCA with x = 0.10 also implies a larger contribution of impurity scattering due to more Co atoms, which may cause stronger pinning of flux lines. The results are analyzed and coincide with theory, including the pinning-induced backflow effect and plastic flow mechanism in vortex dynamics.

Keyword(s): Magnetic Materials (1st) ; Key Technologies (1st) ; Magnetism (2nd) ; J

Note: The authors thank the National Science Council of Taiwan for financial support under Grants No. NSC 98-2112-M-212-001-MY3 (L. M. W.), No. NSC 96-2739-M-213-001, and No. NSC 96-2112-M-007-012 (L.J.C.). T. W. and P. A. acknowledge financial support through the Deutsche Forschungsgemeinschaft (SPP 1458).

---

Contributing Institute(s):

1. Streumethoden (PGI-4)
2. JCNS-FRM-II (JCNS (München) ; Jülich Centre for Neutron Science JCNS (München) ; JCNS-FRM-II)
3. Streumethoden (JCNS-2)

Research Program(s):

1. Grundlagen für zukünftige Informationstechnologien (P42)
2. Großgeräte für die Forschung mit Photonen, Neutronen und Ionen (PNI) (P55)

Experiment(s):

1. No specific instrument

Appears in the scientific report 2011

---

Database coverage:
;

---