Naslov
Flux creep relaxation in single crystal Hg-1201

Autori
Baenitz, M. ; Luders, K. ; Barišić, Neven ; Cho, Y. ; Li. Y. ; Yu, G. ; Zhao, X. ; Greven, M.

Izvornik
Journal of physics. Conference series (1742-6588) 234 (2010); 1-6

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, conference paper, znanstveni

Ključne riječi
Collective pinning theory; Field orientation; Field-cooling; Flux creep; High-Tc cuprates; Higher temperatures; Lower critical field; Magnetization measurements; Mixed state; Pinning mechanism; Powder samples; Supercurrents; Zero-field cooling

Sažetak
Magnetization measurements on a single crystal of the high-Tc cuprate HgBa2CuO4 (Hg-1201) are performed for the two field orientations B||c and B||(a, b). Besides zero-field-cooling (zfc) - field-cooling (fc) and magnetization studies, the flux creep relaxation is determined. The zfc curves exhibit pronounced step-like anomalies in the mixed state above the lower critical field Bc1. They are interpreted as those points in the phase diagram where the penetrating flux fronts meet at the center of the sample. In order to obtain more information about the flux pinning mechanism flux creep relaxation experiments are performed at different temperatures in magnetic fields of 0.15 and 2 T. The resulting supercurrent dependence on the mean activation energy is analysed according to the collective pinning theory which predicts U ((j/jc)-μ -1). The μ- values for B||c are 0.5 at higher temperatures and 2 at 5 K, and they vary between 1.1 and 1.5 for B||(a, b). The observed behaviour is quite different from that found for powder samples

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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