Nuclear Quadrupole and Electronic Heat Capacities of Bismuth

The heat capacity of bismuth has been measured from 0.1 to 2.0°K and found to be represented by $C=2.8\mathrm{}\times {10}^{-7\mathrm{}}{T}^{-2\mathrm{}}+2.1\mathrm{}\times {10}^{-5\mathrm{}}T+1944\mathrm{}{\left(\frac{T}{\theta }\right)}^3$ joules/mole deg with $\theta =120.4-0.6\mathrm{}{T}^2$. The $T^{-2\mathrm{}}$ term in the heat capacity is assumed to be associated with the alignment of the nuclear electric quadrupole moment in the electric field gradient of the crystal and is used to obtain the value 25 Mc/sec for the quadrupole coupling constant. The linear term is used, together with known parameters for the electrons in the conduction band, to obtain an average effective mass for the holes in the valence band of 0.9 times the free electron mass.