Flux flow effects in a nearly reversible type II superconductor

✍ Scribed by O. L. Lange; F. A. Otter

• Publisher: Springer US
• Year: 1975
• Tongue: English
• Weight: 546 KB
• Volume: 18
• Category: Article
• ISSN: 0022-2291
• DOI: 10.1007/bf00116967

✦ Synopsis

Measurements of the Nernst effect over a wide range of magnetic field and temperature in a nearly reversible alloy (Nb8oMozo,T c = 4.15 K, ~ ~-4.1) are reported. Data are presented in the form of vortex transport entropy S d computed from the Nernst effect. At T = 3.5 K, values of Sd(Nernst ) agree well with values of Sd(Ettingshausen ) for fields between about 2Hea and 0.8Hc2, in spite of the fact that pinning forces for current-induced motion exceed those for thermally induced motion by a factor of ten at this temperature. Our measurements indicate that Sd(B -0, T) > Si(B -0, T) for Y ~ 0.63Tc, where S i is the entropy of formation per vortex. Values of Sd(0, T) are compared with low-field theory. The pinning forces are discussed in terms of surface pinning.