Sample-size dependence of the magnetic critical current density in MgB2 superconductors

M. J. Qin; S. Keshavarzi; S. Soltanian; X. L. Wang; H. K. Liu; S. X. Dou

doi:10.1103/PhysRevB.69.012507

← Back to search

Sample-size dependence of the magnetic critical current density in MgB2 superconductors

M. J. Qin, S. Keshavarzi, S. Soltanian, X. L. Wang, H. K. Liu, S. X. Dou

DOI 10.1103/PhysRevB.69.012507 · Physical Review B

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

Sample size dependent magnetic critical current density has been observed in magnesium diboride superconductors. At high fields, larger samples provide higher critical current densities, while at low fields, larger samples give rise to lower critical current densities. The explanation for this surprising result is proposed in this study based on the electric field generated in the superconductors. The dependence of the current density on the sample size has been derived as a power law j∝R1/n [n is the n factor characterizing E−j curve E=Ec(j/jc)n]. This dependence provides one with a method to derive the n factor and can also be used to determine the dependence of the activation energy on the current density.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
MgB2 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown
NdBa2Cu3O7 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown
YBa2Cu3O7 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown