Temperature dependence of the Shubnikov–de Haas effect inHg1−xFexSe

A study of the quantum oscillations in the transverse magnetoresistance (Shubnikov–de Haas effect) in oriented single crystals of ${\mathrm{Hg}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{Fe}}_{\mathrm{x}}$Se with x∼0.05 has been made as a function of temperature (1.3<T<35 K) and for magnetic fields less than 5 T. Significant differences in the temperature dependence of the amplitude of the oscillations for magnetic fields oriented along [110] and [111] have been observed. Data obtained at low temperatures and for H→∥[111] reveal a sequence of zeros that suggest two separate sheets of the Fermi surface for this orientation.