Critical currents and relaxation effects in Nd2 − xCexCuO4 − y single crystals

✍ Scribed by J. Fontcuberta; S. Piñol; X. Obradors; F. Lera; C. Rillo

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 383 KB
• Volume: 30
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(90)90304-u

✦ Synopsis

Inductive critical current and field cooled (FC) magnetic relaxation measurements were carried out on a Nd2_xCe,CuO4_v (x = 0.15) single crystal for H II c. A zero field Jc N value of 1.5 x 104 A cm -2 was obtained at 4.2 K, together with logarithmic magnetic field dependence. The relaxation data collected after a FC process revealed a logarithmic time dependence. At 4.2 K two clearly different time dependences were observed over distinct time scales. The corresponding thermal activation energies, Uo", for flux creep were found to be =3 and 1 meV, which are much smaller than typical values found for other high temperature superconductors. A.c. susceptibility data show a two step diamagnetic response below Tc and complete magnetic shielding at 4.2 K and 1.10e. The d.c. susceptibility (H --40e) reveals unusual behaviour near Tc and paramagnetic rare earth polarization at 4.2 K.