Magnetophonon Effect inn-TypeHg1−xCdxTe (x=0.212)

Abstract

We report measurements of the magnetic field positions of magnetophonon-oscillation peaks on samples of $n$-type ${\mathrm{Hg}}_{1-x}{\mathrm{Cd}}_x\mathrm{Te} \mathrm{}(x=0.212\mathrm{})\mathrm{}$. The band-edge effective mass $m^{*}\mathrm{}\left(0\right)=0.005\mathrm{}{m}_0$ and the effective $g$ factor $g^{*}\mathrm{}\left(0\right)=-172\mathrm{}$ are deduced from low-temperature Shubnikov-de Haas measurements. The temperature dependence of the magnetophonon peaks is interpreted using a nonparabolic band model with a temperature-dependent energy gap and a temperature-dependent band-edge effective mass. A large positive temperature coefficient $\frac{d{\epsilon }_g}{\mathrm{dT}}=+7.6\mathrm{}\times {10}^{-4\mathrm{}}$ eV/K is required to fit the experimental data.