Studies of Dielectric Properties and Band Parameters of N-Pb_1-<i>x</i>Sn_<i>x</i>Te by Magnetoplasma Waves

Abstract

From magnetoplasma experiments at 50 GHz for n -Pb 1- x Sn x Te (0≤ x < 0.3), a static dielectric constant ε s is determined as a function of x . For x =0, 0.063, 0.091, 0.152 and 0.293, ε s is found to be 1410, 1770, 2840, 4610 and 10800 at 1.6 K, respectively. ε s seems to depend on band gap as well as on carrier density. It is suggested that free carriers tend to stabilize the lattice instability and that the transition to the ferroelectric phase would be possible at around x =0.2 if the carrier density would be very small. It is further found that the band structure of alloys is essentially the same as that of PbTe at least up to x =0.3.