Magnetotransport investigations at InSb and Hg1-xCdxTe bicrystals in tilted magnetic fields
The Hall effect and the Shubnikov-de Haas effect of a quasi-two-dimensional inversion layer adjacent to grain boundaries in InSb and Hg0.23Cd0.77Te bicrystals are investigated in magnetic fields up to 14.5 T, temperatures down to 0.4 K and at different angles between the grain boundary plane and the magnetic field. For magnetic fields perpendicular to the grain boundary interface a complicated pattern of Shubnikov-de Haas oscillations and well developed quantum Hall plateaux with the quantum numbers j=7 and j=9 are observed at an HgCdTe sample. A cosine dependence of the Hall coefficient and the oscillation period of the ground subband in tilted fields was found for both InSb and HgCdTe bicrystals, whereas the first excited subband showed remarkable deviations from the two-dimensional behaviour. From these deviations, an estimate of the spatial extension of the wavefunction is given. The diamagnetic Shubnikov-de Haas effect yields depopulation fields which can be explained within the Reisinger-Koch model. First results of cyclotron resonance measurements show well separated transmission dips for different subband masses at HgCdTe bicrystals.