Anisotropy of the generalized Ginzburg-Landau parametersx1andx2in clean, cubic, type II superconductors
✍ Scribed by K. H. Berthel; B. Pietrass
- Publisher
- Springer US
- Year
- 1978
- Tongue
- English
- Weight
- 340 KB
- Volume
- 33
- Category
- Article
- ISSN
- 0022-2291
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✦ Synopsis
From the nonlocal GLAG theory expressions are derived for :~1 and x2 of a clean, cubic crystal with a general Fermi surface. In the region of weak nonlocality near Tc the correction terms in Hc2, ~1, and *:2 due to the nonspherical Fermi surface are expressed by two dimensionless Fermi surface averages. For highly purified Nb single crystals and polycrystalline Nb samples, *:t and *:2 were determined from magnetization measurements in the temperature range (0.3-0.95)Tc. The experimental data show that the orientation dependence in *:2 is twice as large as in *:1, in agreement with the theoretical result near T~. The two Fermi surface averages that characterize the anisotropy of He2, x,, and *:2 near Tc are estimated from experimental data for Nb and V.