Galvanomagnetic effects and alloy scattering in n‐type Pb_1–xSn_xTe at low temperatures

Abstract

Galvanomagnetic effects are investigated in n-type Pbl -,Sn,Te with comparatively low carrier concentration (1.4 x 10' ' t o 3.5 x 10'8cm-3) grown from the melt. From the analysis of the longitudinal and transverse magnetoresistances and Hall coefficient a t low temperatures together with the Shubnikov-de Haas data, it is found that the scattering is very much isotropic in spite of the large anisotropy of the effective mass. Further analysis of the scattering relaxation time, z, indicates that the alloy scattering is dominant a t low tmperatures. The inatrix elements of the alloy scattering potential a t the band edges are deduced; U,(Pb-Sn) = 8.

The disorder scattering in zincblende narrow‐gap semiconducting mixed crystals

“…It was found in [30] that for Hgo.8Cd0.2Te n, = = 1.9 X 1013 and for Pbo.6Sno.2Te n, = 9.3 x 1013 cm-3 while for the values of the parameters used in [30] these critical concentrations are n, = 2.1 x 1021 and 1.0 X x ~m -~, respectively. The conclusion that above n, x 1013 ~m -~ the disorder scattering is of no importance is in direct contradiction with the experimental data of Takita et al [15] where the Pbl-,Sn,Te samples with n x l W 7 to 10l8 were measured and disorder scattering was found to be particularly important.…”

Intraband absorption in lead chalcogenide mixed crystals

“…The parameters of four samples (see [5] It is interesting to compare our results with other mechanisms which contribute to the intraband absorption. As it was already mentioned, the free carrier absorption due to ionized impurities can be neglected.…”

“…Fourfold integrals could be performed numerically. As an example we have calculated the absorption coefficient for four sainples Pblp,Sn,Te using the parameters presented in Table 1 ; we also take erg cm3, Uv = 3Uc (see [ 5 ] ) . Our calculations are performed for the case of a strongly degenerate electron gas.…”

“…Our calculations are performed for the case of a strongly degenerate electron gas. The parameters of four samples (see [5]) a t 4.2 K. n electron concentration, m l p and mllF effective masses a t the Fermi level (eB Fermi energy), n~j o and mjlo effective masses a t the conduction band edge versus frequency for samples 2-1 ( -) a n d 2-2 (---)…”

“…There is a number of papers in which the importance of the composition fluctuations (chemical disorder) on the carrier scattering is shown. For example Ge-Si mixed crystals were investigated by Glicksman [3] and by Levitas [4], lead chalcogenide alloys were studied in [ 5 ] , and ATJB'I compounds in [6].…”