| Superlattice growth of the semimetal-semiconductor system, Bi and CdTe, by high vacuum evaporation onto Bi and PbTe buffer layers on Muscovite mica substrates has been successfully achieved for the first time. The modulation wavelengths grown were sensitive to the substrate temperature which varied between 83 and 104$spcirc$C. Superlattices with Bi layer thicknesses from 31 to 142A and CdTe layer thickness from 80 to 92A were grown on PbTe buffers for transport measurement studies. These structures exhibited 3 orders of satellites in the $theta$-2$theta$ x-ray diffraction analysis. Laue x-ray diffraction analysis showed that the superlattices exhibited a well defined epitaxy with the (111) planes of the superlattice parallel to the (00.1) planes of mica in a twinned orientation 180$spcirc$ apart.;Analysis of the transport property measurements showed that the resistances at low temperature ($<$10K) varied logarithmically with temperature, while the perpendicular and parallel magnetoresistance data exhibited log H dependence. This behavior was consistent with the predictions of 2D electron transport for Weak Localization and Coulomb Correlation theories in the presence of strong spin-orbit interactions. The temperature and low magnetic field ($<$1 Tesla) dependence of resistance was dominated by localization effects. The perpendicular magnetoresistance data was fitted very well by the anisotropic spin-orbit scattering time expression of Weak Localization with Zeeman spin splitting effects included. The inelastic scattering time $tausb{rm i}$ and the x and z components of the spin-orbit scattering time ($tausb{rm so}$) were extracted from the fits. The values $tausb{rm i}$, $tausb{rm x}$, and $tausb{rm z}$ agree well with earlier bismuth thin film studies. A transition region is observed occurring around 50A in which the ratio $tausb{rm x}/tausb{rm z}$ increases from 1 to roughly 7 as the bismuth layer thickness decreases, an indication of a 3D to 2D transition of $tausb{rm so}$. The temperature dependence of the inelastic scattering time, $tausb{rm i}$, was determined to be $alpha$ T$sp{rm -1}$. This result was derived from both an analysis of the resistance temperature dependence and fits to the perpendicular magnetoresistance data at different temperatures. Analysis of the Hall effect data shows high carrier concentrations and poor Hall mobilities. Tellurium diffusion across the interfaces is most likely the major contribution to the disorder and doping of the films. |
