Magnetoplasma Waves in Bismuth and Semimetallic BiSb Alloys at Microwave Frequencies 9 to 100 GHz

On the first time extensive investigation of magnetoplasma waves is reported for the whole semimetallic range of the alloy BiSb (0 ≦ x ⪅ 6 at% Sb). It is possible to deduce the qualitative, in some cases as well the quantitative, behaviour with alloy composition of the so‐called mass‐density function under the condition that this quantity is independent of the applied magnetic field. This is achieved by appropriate variation of the microwave frequency in the range 9 to 106 GHz, the sample thickness and, finally, the field configuration of the measurement. The determination of the magnetic field independent mass density function turns out to be difficult for alloys with an antimony concentration close to the one for the semimetallic to semiconducting phase transition.