Oscillatory Magnetoresistance in Mercuric Selenide

Abstract

The oscillatory magnetoresistance (Shubnikov-de Haas effect) in oriented single crystals of mercuric selenide was measured at 1.2 and 4.2\ifmmode^\circ\else\textdegree\fi{}K and in transverse magnetic fields up to 25 kG. Analysis of the periods of the oscillations for the magnetic field aligned with $〈110〉$, $〈111〉$, and $〈100〉$ crystallographic directions showed that the Fermi surface for conduction electrons in HgSe, although nearly spherical, has slight bulges in the $〈111〉$ directions of k space. From the temperature dependence of the amplitudes of the oscillations, it was determined that the cyclotron effective masses of conduction electrons at the Fermi surface ranged from 0.033 to 0.068 ${m}_{e}$ for samples having from 1.86\ifmmode\times\else\texttimes\fi{}${10}^{17}$ to 4.52\ifmmode\times\else\texttimes\fi{}${10}^{18}$ electrons/${\mathrm{cm}}^{3}$. This variation of effective mass with electron concentration is consistent with the nonparabolic conduction-band model developed for compounds that have the zincblende crystal structure. The band parameters derived are $p=7.1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$ eV cm and ${E}_{G}=0.24$ eV, where $P$ is an interband momentum matrix element and ${E}_{G}$ is the band gap at k=0; these values are in fair agreement with parameters deduced from reflectivity data by other investigators.