The Hall mobility of excess electrons in 2,2-dimethylbutane, 2,2,4-trimethylpentane, and 2,2,4,4,-tetramethylpentane

Abstract

The Hall mobility (μH) of excess electrons was measured in liquid 2,2-dimethylbutane (22DMB), 2,2,4-trimethylpentane (224TMP), and 2,2,4,4-tetramethylpentane (2244TMP) at temperatures from 20 to 160 °C. Drift mobilities μD were also measured over this temperature range. At 20 °C the observed values of μH for 22DMB, 224TMP, and 2244TMP are 12, 22, and 32 cm2/V s, respectively. In all three liquids μH increases with temperature. The comparison of μH and μD indicates that electron traps are absent in 22DMB and 2244TMP. In contrast, in 224TMP μH is about 3.5 times μD at 18 °C. Thus, in this liquid, traps are present and the concentration of traps is about one per thousand solvent molecules. The Hall mobility results are in reasonable accord with the expectations of the deformation potential model and support the concept of scattering of electrons in the conduction band due to density fluctuations.