Magneto-resistance and vortex phase diagram of BaNi sub(0.1)Fe sub(1.9)As sub(2) single crystal

• Published in: Chinese physics B Vol. 23; no. 12; pp. 127402 - 1-127402-5
• Main Authors: Lu, Jun-Chao, Yu, Yi, Pi, Li, Zhang, Yu-Heng
• Format: Journal Article
• Language: English
• Published: 01.12.2014
• Subjects: Creep (materials); Electrical resistivity; Fluid flow; Glass; Magnetic fields; Phase diagrams; Pinning; Vortices
• ISSN: 1674-1056; 1741-4199
• DOI: 10.1088/1674-1056/23/12/127402

The transition from vortex glass to a liquid phase is studied in BaNi sub(0.1)Fe sub(1.9)As sub(2) single crystal with T sub(c) = 19.4 K by magneto-resistance measurements. The resistivity curves are measured in magnetic fields in a range of 0 T-13 T for H || c and H[perpendicular]c. Good scalings for all values of resistivity [rho](H,T) and the effective pinning potential U sub(0)(H,T) are obtained with the modified vortex glass theory by using the critical exponents s and H sub(0). Phase diagrams for H || c and H[perpendicular]c are determined based on the obtained vortex glass temperature T sub(g), the vortex dimensionality crossover temperature T*, and the upper critical magnetic field H sub(c2). Our results suggest that both below and above 5 T. single vortex pinning co-exists with collective creep, and collective creep is dominant. There is a narrower vortex liquid region for H[perpendicular]c than for H || c in the vortex phase diagram, which may originate from a stronger pinning force.