Atomic Heats of Normal and Superconducting Tin between 1.2° and 4.5°K

Atomic heat measurements on tin in the normal and superconducting states revealed that the electronic contribution to the atomic heat in the superconducting state, C₄ₒ, could be represented below about 0. 7T₂ by the same exponential expression found applicable to vanadium: C₄ₒ{T₂}=ae^-b{T₂T}, with a=9. 17 and b=1. 50. The deduced curve of critical field vs temperature was in good agreement with H₂-T curves reported from magnetic measurements. The critical field extrapolated to the absolute zero, H₀, was 303. 4 oersteds and the transition temperature was 3. 722^. Below 2. 5^ the normal atomic heat could be represented by the Sommerfeld-Debye expression with =1. 7510^-3 joule mole^-1 deg^-2 and =195. 0^K; above 2. 5^ deviation from this expression indicated that decreased with increasing temperature.