Anisotropy of the superconductive to normal transition in tantalum-nitrogen single crystals

✍ Scribed by J. F. Sporna; E. Seidl; H. W. Weber

• Publisher: Springer US
• Year: 1979
• Tongue: English
• Weight: 760 KB
• Volume: 37
• Category: Article
• ISSN: 0022-2291
• DOI: 10.1007/bf00113876

✦ Synopsis

Systematic experiments on the transition to the normal state in superconducting tantalum single crystals doped with interstitially dissolved nitrogen impurities are presented. On the low-K side of the magnetic phase diagram, where at some low temperature 0 < T* < Tca transition from type I to type II superconductivity occurs, a new effect .has been observed, as reported briefly elsewhere: because of the correlation of Hoe with crystal directions, at fixed temperatures near T*, whether the sample is a type I or a type Il superconductor depends on which crystal direction is oriented parallel to the external field. In the type H superconducting range all samples display an Hoe anisotropy effect, which is commonly observed in cubic superconductors, even in the extreme dirty limit (a ~ 12). However, the second anisotropy coefficient (l = 6 component) is found to be negligibly small in all tantalum samples. 639 oo22-2291/79/12oo-o6395o3.oo/o