Linear dependence of the Hall coefficient of 1% Na doped PbTe with varying magnetic field

Heavily p-doped PbTe is known to be a highly efficient thermoelectric material and theories explaining this have connected it to positive curvature in the Seebeck coefficient between 300 and 500 K and a peak in the Hall coefficient at 500 K due to band convergence. Recent work by Jaworski et al. has suggested that a pocket of high mobility electrons between the L and Sigma point in the Brillouin zone are responsible for these effects, inferred from an observed inversion of the Hall resistivity under small magnetic fields (<0.5 T). Here the Hall resistivity of 1% Na doped PbTe is measured in magnetic fields ranging from 0.1 to 2 T at 293 and 626 K and found to be linear without any inversion of Hall resistivity.