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The transition from vortex glass to a liquid phase is studied in Ba Ni0.1Fe1.9As2 single crystal with Tc = 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⊥c. Good scalings for all values of resistivity ρ(H, T) and the effective pinning potential U0(H, T) are obtained with the modified vortex glass theory by using the critical exponents s and H0. Phase diagrams for H c and H⊥c are determined based on the obtained vortex glass temperature Tg, the vortex dimensionality crossover temperature T*, and the upper critical magnetic field Hc2. 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⊥c than for H c in the vortex phase diagram, which may originate from a stronger pinning force.
The transition from vortex glass to a liquid phase is studied in Ba Ni0.1Fe1.9As2 single crystal with Tc = 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⊥c. Good scalings for all values of resistivity ρ (H, T) and the effective pinning potential U0 (H, T) are obtained with the modified vortex glass theory by using the critical exponents s and H0. Phase diagrams for H c and H⊥c are determined based on the obtained vortex glass temperature Tg, the vortex dimensionality crossover temperature T *, and the upper critical magnetic field Hc2. 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⊥c than for H c in the vortex phase diagram, which may originate from a stronger pinning force.