MAGNETOPLASMA WAVES IN BISMUTH AND SEMIMETALLIC BISB ALLOYS IN STRONG MAGNETIC-FIELDS AT 300-GHZ

An experimental study of the propagation of magnetoplasma waves in pure Bi and in semimetallic BiSb alloys at 300 GHz is presented for magnetic fields up to 65 kG. The magnetic field is parallel to the sample surface and perpendicular to the E vector of the incoming high-frequency wave. Alloys in the range from pure Bi to a concentration of 2.35 at.% Sb are considered. Both binary sample surfaces as well as trigonal sample surfaces are examined for a magnetic field direction along each of the main crystallographic axes. From the experimentally determined dispersion curves for the magnetoplasma waves the magnetic field value at which the electrons enter the quantum limit is deduced, and the mass density function falpha alpha j(B) is found. A possible variation of the lattice dielectric constant epsilon 3 with Sb concentration is suggested. The experimental results indicate that the classical Alfven dispersion is not always obeyed.