Figures of merit of bismuth under conditions of strong phonon drag

Thermomagnetic effects are known to be large in bismuth near 4.2°K where strong phonon drag phenomena are believed to occur. The figures of merit of bismuth are analyzed in terms of the individual transport coefficients for varying extrinsic carrier concentrations and magnetic fields. Using available data and current theory, it is concluded that the figures of merit are insufficient to enable useful cooling to be obtained from a bismuth device operating in a temperature region of strong phonon drag.