Between 0.96 and 2.3°K the atomic heat of a polycrystalline ingot of bismuth (99.99 percent) can be represented by: $c=(1.213\mathrm{}\pm 0.006)T^3+(0.078\mathrm{}\pm 0.03)T$ millijoules/mole deg. The lattice contribution, given by the cubic term, corresponds to 117°K for the low-temperature Debye $\theta$. Between 2.3 and $4.2°\mathrm{K}\theta$ decreases to 105°K. The electronic contribution is much smaller than for normal metals.

• Received 19 July 1954

DOI:https://doi.org/10.1103/PhysRev.96.897