Critical-current enhancement in particle-irradiated cuprate semiconductors

Abstract

Detailed measurements have been made of the magnetic field (0<H<6 T) and temperature (10 K<T<100 K) dependencies of the critical current density jc in Tl2CaBa2Cu2O8 films before and after irradiation with incremental fluences (0<Φ<3×1016 cm−2) of 2 MeV protons. The results are interpreted quantitatively in terms of radiation-induced changes in (1) the critical temperature, (2) the rate of thermal flux creep, and (3) local scale superconductivity. Radiation-induced enhancements in jc are described by an expression which allows the fluence that maximizes jc to be predicted as a function of H, T, pinning energy, and particle type.

Enhancement of Pinning Energy and Critical Current Density in Tl2CaBa2Cu2O8 Films by Proton Irradiation

“…reduction in good superconducting material, but this suppression is offset by an increase in the pinning energy.The measurements reported here, when combined with the zero-field observations of Ref 6,. illustrate a delicate interplay between radiation-induced enhancement of the pinning energy and radiation-induced damage of some fraction of the 699 (1) j c-[I3.-TI/Tc(,t) ] 1/2exp, (-at) superconducting material.…”

“…6, the combined effect of these two influences is shown to follow the functional dependence where a = 7.5 ± 0.9 x 10-17 cm 2 . We have scaled the pinning force density by the functional dependence of Eq.…”

“…[6] To explore these effects, we have made detailed measurements of the irreversibility line via ac susceptibility measurements at 10 KHz and of the pinning force density via critical current measurements in magnetic fields applied parallel to the c-axis.…”

Correlation of intermediate ion energy induced extended defect continuity to enhanced pinning potential in Tl-2212 films

“…Irradiation that generates point defects can enhance J, at low fluences; however, as fluence is increased T, decreases and an increase normal state resistivity results [5, [6]. Considerable less improvement was observed in T1-2212 films for 2 MeV protons [7]. A microstructural study with HRTEM showed damage by 1.…”