Small anisotropy, weak thermal fluctuations, and high field superconductivity in Co-doped iron pnictide Ba(Fe1-xCox)(2)As-2

Yamamoto, A; Jaroszynski, J; Tarantini, C; Balicas, L; Jiang, J; Gurevich, A; Larbalestier, DC; Jin, R; Sefat, AS; Mcguire, MA; Sales, BC; Christen, DK; Mandrus, D

HERO ID

4797519

Reference Type

Journal Article

Year

2009

HERO ID 4797519
In Press No
Year 2009
Title Small anisotropy, weak thermal fluctuations, and high field superconductivity in Co-doped iron pnictide Ba(Fe1-xCox)(2)As-2
Authors Yamamoto, A; Jaroszynski, J; Tarantini, C; Balicas, L; Jiang, J; Gurevich, A; Larbalestier, DC; Jin, R; Sefat, AS; Mcguire, MA; Sales, BC; Christen, DK; Mandrus, D
Journal Applied Physics Letters
Volume 94
Issue 6
Abstract We performed high-field magnetotransport and magnetization measurements on a single crystal of the 122-phase iron pnictide Ba(Fe1-xCox)(2)As-2. Unlike the high-temperature superconductor cuprates and 1111-phase oxypnictides, Ba(Fe1-xCox)(2)As-2 showed practically no broadening of the resistive transitions under magnetic fields up to 45 T. We report the temperature dependencies of the upper critical field H-c2 both parallel and perpendicular to the c-axis, the irreversibility field H-irr(c)(T), and a rather unusual symmetric volume pinning force curve F-p(H) suggestive of a strong pinning nanostructure. The anisotropy parameter gamma=H-c2(ab)/H-c2(c) deduced from the slopes of dH(c2)(ab)/dT=4.9 T/K and dH(c2)(c)/dT=2.5 T/K decreases from similar to 2 near T-c, to similar to 1.5 at lower temperatures, much smaller than gamma for 1111pnictides and high-T-c cuprates.
Doi 10.1063/1.3081455
Wosid WOS:000263409400068
Is Certified Translation No
Dupe Override No
Is Public Yes
Keyword barium compounds; cobalt compounds; doping profiles; fluctuations in superconductors; flux pinning; galvanomagnetic effects; high-temperature superconductors; iron compounds; magnetic anisotropy; magnetisation; nanostructured materials; superconducting critical field; superconducting transition temperature; superconducting transitions