Quantitative understanding of the enhanced irreversibility line and critical current density due to linear defects in Bi2Sr2CaCu2O8 single crystals with the vortex dimensionality-crossover model

摘要

We show that the 3D-to-2D crossover model of Kim et al. (Physics C177, 431, 1991) provides a quantitative understanding of recent results of Thompson et al. (Appl. Phys. Lett. 60, 2306, 1992) for both the enhanced irreversibility line and critical current density, J(sub c), in single-crystalline Bi(sub 2)Sr(sub 2)CaCu(sub 2)O(sub 8) after heavy-ion irradiation. Fits of the irreversibility lines indicate that these linear defects increase the pinning energy by a factor of (approximately)4, which is also consistent with the low-temperature J(sub c) enhancement. Dependence of the pinning effectiveness on the nature of artificial or natural pinning sites is discussed.