Upper critical field and thermally activated flux flow in LaFeAsO1-xFx

Authors

Mahboobeh Shahbazi, University of WollongongFollow
Xiaolin Wang, University of WollongongFollow
C Shekhar, Banaras Hindu University India
O N. Srivastava, Banaras Hindu University India
Z W. Lin, Univ Technol Sydney
J G. Zhu, Univ Technol Sydney
S. X. Dou, University of WollongongFollow

RIS ID

37703

Publication Details

Shahbazi, M., Wang, X. L., Shekhar, C., Srivastava, O. N., Lin, Z. W., Zhu, J. G. & Dou, S. X. (2011). Upper critical field and thermally activated flux flow in LaFeAsO1-xFx. Journal of Applied Physics, 109 (7), 07E162-1-07E162-3.

Abstract

The magneto-resistance, critical current density, J_c, upper critical field, H_c2, and flux pinning properties of LaFeAsO_1−xF_x superconductors were investigated systematically by magnetic and magneto-transport measurements in the fields up to 13 T over a temperature range of 5–35 K. It was found that the H_c2 increased with increasing fluorine concentration up to x ≤ 0.15, while with higher fluorine doping, H_c2 decreased. A peak effect in the J_c as a function of field was observed at T  U_o, scales as U_o/k_B ∝ B⁻ⁿ with n = 0.13 for B n =− 0.68 for B > 1 T for LaFeAsO_0.85F_0.15.

Grant Number

ARC/DP0770205

Additional Grant Number

http://purl.org/au-research/grants/ARC/DP0770205