Flux lattice melting in twinned single crystals
Superconductivity Research Laboratory, ISTEC, 10-13 Shinonome 1-Chome, Koto-ku, Tokyo
Accepted: 7 April 1999
We report on the observation of a first-order melting transition of the flux line lattice in a twinned single crystal by transport and magnetization measurements. The position of kink and hysteresis in resistance, and magnetization jump coincides in the B-T plane. The observed melting transition is a strong function of partial pressure during growth. The first-order transition gradually becomes continuous and a peak in critical current density first emerges with oxygen partial pressure to Ar atmosphere. The melting line shifts to the low-temperature side due to increasing disorders. The results suggest that the twin planes do not suppress the melting transition in a clean crystal. Our results also demonstrate the existence of a first-order melting transition in a twinned RE-123 system containing rare-earth magnetic ions.
PACS: 74.60.Ge – Flux pinning, flux creep, and flux-line lattice dynamics / 74.60.Jg – Critical currents / 74.25.Fy – Transport properties (electric and thermal conductivity, thermoelectric effects, etc.)
© EDP Sciences, 1999