Superconductivity of Thorium below l°k

The critical magnetic field of thorium has been determined between. 0.1°k and 1.37°k, the transition temperature, where the initial slope of the critical field curve is 190 gauss/deg. The data indicate a value of 162 gauss for the critical field at absolute zero. The critical field curve departs from a parabola near the transition temperature. The electronic specific heat, 11.1×10−4 T cal/mole-deg, deduced from the magnetic measurements is in substantial agreement with the previously determined calorimetric value.