Single superconducting energy gap in pure niobium

✍ Scribed by V. Novotny; P. P. M. Meincke

• Publisher: Springer US
• Year: 1975
• Tongue: English
• Weight: 541 KB
• Volume: 18
• Category: Article
• ISSN: 0022-2291
• DOI: 10.1007/bf00116976

✦ Synopsis

The quantities characterizing the superconducting behavior of very pure niobium determined from the specific heat measurement are T c = 9.26 +_ 0.01 K, Cps = (0.091 +_ O.O01)T 3 below 3 K, AC(Tc) = 140 +_ 4 mJ/mole K, 2A(0)/kT c = 3.65 + 0.04, Hc(0) = 2061 +_ 30 G, and dHc/dT = 419.3 +_-3 G/K at T = T c. Principal discrepancies with previous measurements are the absence of an anomalous specific heat at low temperatures in higher purity niobium and a sharp discontinuity at the superconducting transition temperature. A sample with lower purity exhibited an excess specific heat at temperatures below 2.3 K but of smaller magnitude than previously reported.