Magnetoresistance of Crystalline Mercury

The magnetoresistance of single crystals of high-purity mercury has been investigated at a temperature of 1.3°K in applied magnetic fields up to 23 kOe. Plots showing magnetoresistance as a function of magnetic field direction showed narrow minima for directions of magnetic field in certain angular ranges in planes normal to $〈100〉$, $〈1\overline{1}0〉$, $〈110〉$, and $〈123〉$ directions of reciprocal space. These minima are attributed to primary periodic open orbits along $〈100〉$ directions, secondary periodic open orbits along $〈110〉$ and $〈1\overline{1}0〉$ directions and a small band of periodic orbits along $〈123〉$ directions. Broad subsidiary minima were observed and are attributed to higher order orbits. The trajectories of the open orbits are shown on Keeton and Louck's model of the first-zone hole surface of mercury. The analysis shows that the radius of the opening in the (111) face of the model is (0.14±0.03) ${\mathrm{\AA }}^{-1\mathrm{}}$.