Some thermal and magnetic properties of tantalum, niobium, and vanadium at helium temperatures

✍ Scribed by A. Calverley; K. Menclelssohn; P.M. Rowell

• Publisher: Elsevier Science
• Year: 1961
• Tongue: English
• Weight: 618 KB
• Volume: 2
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(61)90008-x

✦ Synopsis

PREVIOUS measurements of the thermal conductivity of these metals have been made in both the superconductive and normal state between 2 and 4 ° K by Mendelssohn and Olsen ~ and Rosenberg. 2 Inconsistent results have been reported for the critical field values and this agrees with the conclusions that the superconductive properties of these elements are strongly dependent on the method by ,~vhich the specimens are prepared. All these metals have high melting points and also rapidly absorb gaseous impurities when heated.

This systematic investigation of these three superconductors was stimulated by the rather surprising difference which had been observed between two tantalum specimens) One of these was polycrystalline while the other was a zone refined single crystal. The zone refining technique has been extended to niobium and vanadium and the same behaviour was then observed for each metal. The underlying mechanisms responsible for this behaviour are comparable with those in similar measurements on lead and a lead alloy reported in another paper. 4 Some of the present results have been summarized earlier. 5