Pinning analyses of a BaHfO₃-containing GdBa₂Cu₃O_7‐δ thin film grown by chemical solution deposition

Abstract

The electric transport properties of a GdBa 2 Cu 3 O 7−δ thin film containing 12 mol% nano-sized BaHfO 3 (BHO) particles grown by chemical solution deposition were investigated in a wide range of temperatures (4.2 ≤ T ≤ 77 K) and magnetic fields up to µ 0 H=19 T. The exponent n of the electric field-current density characteristics (E∝J n ) has the following relation (n-1)∝J α c (α∼0.45) irrespective of measurement temperature for H ∥ c. On the other hand, this relation does not hold for H ∥ ab. The angular dependence of J c was almost similar to that of n except for the angle close to the ab-plane. A dip of n around this angle regime was observed below 77 K, whereas J c exhibited a maximum. At T ≤ 50 K a tiny peak in the dip was observed that grew with decreasing temperatures. These results suggest that the pinning mechanism changes with temperature for H ∥ ab.

Effect of carbon doping on magnetic flux pinning and superconducting performance in FeSe0.5Te0.5 single crystals

“…In order to shed light on the pinning mechanisms in the field region of the SMP in our samples, we studied the magnetic field dependence of the pinning force density F p . f p = F p /F p,max is plotted as a function of reduced field h = H/H max instead of H/H irr (as is usual for hightemperature superconductors) [30,31] in figure 5(a), where F p,max = F p (H = H max ) is the maximum of F p . This allows us to analyze the pinning mechanism even though J c could not be measured up to H irr .…”