Critical Field Measurements on Superconducting Lead Isotopes

摘要: The measurement of the isotope effect uppn superconducting critical field lead was extended from T/sub c/ to 1.28 K, and an accurate critical- curve for is reported this temperature range. measured critical-fie1d expanded as a function T/sup 2/ used in calculating thermodynamic properties lead. values coefficient electronic specific heat normal state latent transition are good agreement with calorimetric measurements. does not show exponential 1/T dependence but instead close resemblance 4/ below 5 K. lead, like that most superconductors, parabolic. However, observed H/sub 1ie above parabola passing through O/ which opposite direction deviations shown by all other superconductors precise data available. It empirical correlation exists between deviation parabolic behavior c// THETA /sub O/, where Debye at Tmore » = O Measurements upon small differences heat, gamma , specimens general give support principle similarity about same precision has been superconductors. (auth)« less