Pressure-dependent magnetoreflection studies of Bi andBi1−xSbxalloys

Abstract

Pressure-dependent magnetoreflection results for Bi and ${\mathrm{Bi}}_{1\ensuremath{-}x}{\mathrm{Sb}}_{x}$ ($x=0.05,0.15$) alloys are reported for pressures up to 3 kbar at 77 K, for $\stackrel{\ensuremath{\rightarrow}}{\mathrm{H}}$ parallel to the binary axis and using a C${\mathrm{O}}_{2}$ laser source operating at 10.6 \ensuremath{\mu}m. The results are interpreted to yield values for the pressure dependence of the $L$-point energy gap and the band-edge cyclotron effective mass. The analysis shows that the pressure dependence of $\frac{{E}_{g}}{{{m}_{c}}^{*}}$ dominates the pressure-dependent magnetoreflection spectra, a result of significance because previous pressure-dependent Fermi-surface studies have assumed $\frac{{E}_{g}}{{{m}_{c}}^{*}}$ to be pressure independent. Furthermore, the analysis shows that the magnitudes of the individual pressure derivatives $\frac{d{E}_{g}}{\mathrm{dp}}$ and $\frac{d{{m}_{c}}^{*}}{\mathrm{dp}}$ are very sensitive to $\frac{d(\frac{{E}_{g}}{{{m}_{c}}^{*}})}{\mathrm{dp}}$ for these materials.