Title: Upper critical field of granular SnGe samples near the superconductor-to-insulator transition
Authors: Lin, PJ
Hsu, SY
電子物理學系
Department of Electrophysics
Issue Date: 1-Jun-2005
Abstract: We have measured the upper critical field, H-c2(T), in granular SnGe samples with normal state resistivities, rho(N), that range from 0.3 m Omega cm to 0.5 Omega cm. The samples demonstrate an evolution from superconducting to insulating in transport with increasing disorder. The temperature dependence of H-c2 shows a clear change in curvature between high rho(N) and intermediate rho(N) samples differing from the experimental results by Deutscher et al.. Our data is analyzed in terms of Ginzburg-Landau theory and grain structure induced disorder effect. The result is similar to the observation in high T-c superconductors that anisotropy induced fluctuation effect play an important role.
URI: http://hdl.handle.net/11536/13626
ISSN: 0577-9073
Journal: CHINESE JOURNAL OF PHYSICS
Volume: 43
Issue: 3
Begin Page: 662
End Page: 665
Appears in Collections:Conferences Paper