W. Kraak

Shubnikov-de Haas effect of n-inversion layers in InSb grain boundaries

Abstract Hall effect and Shubnikov-de Haas effect have been investigated in a n-inversion layer adjacent to the grain boundary in p-InSb bicrystals. The observed quantum oscillations of the magnetoconductivity result from a superposition of the Shubnikov-de Haas effect in two occupied subbands. The electron densities of the subbands nsi(ns1=3.5 × 1011 cm-2;ns0= 1.1 × 1012cm-2) and the effective cyclotron mass of the lower subband mc0=(0.023 ± 0.002)m0 have been evaluated.

Flux growth of Bi-Sr-Ca-Cu-O whiskers

Fibrous single crystals of Bi-Sr-Ca-Cu-O have been grown from the melt of the corresponding oxides and carbonates. The crystals are mostly flat ribbon-like whiskers with the long edge in the a direction and the c axis perpendicular to the face. There exists a superstructure in the b direction. Dislocations observed are mainly parallel in the a axis. The whiskers are elastic and they can be bent with a radius of curvature of down to 0.02 mm. The whiskers show a single-phase behaviour in the temperature dependence of the electrical resistivity with a critical temperature Tcm=81.5 K.

POSITIVE MAGNETORESISTANCE AND HOLE-HOLE SCATTERING IN GAAS/AL0.5GA0.5AS HETEROSTRUCTURES UNDER UNIAXIAL COMPRESSION

Resistance, magnetoresistance and their temperature dependencies have been investigated in the 2D hole gas at a [001] p-GaAs/Al

Modification of the energy spectrum and magnetic breakdown in a system of 2D holes at the GaAs/Al0.5 Ga0.5As heterojunction upon uniaxial compression

_{0.5}

Cyclotron resonance of the quasi-two-dimensional electron gas at Hg1-xCdxTe grain boundaries

Ga

Relaxation of low-temperature negative photoconductivity in p-GaAs/Al0.5Ga0.5As: Be and deep traps near the heterointerface

_{0.5}

Two-dimensional electrons at the n-GaAs/AlxGa1−xAs heterointerface under uniaxial compression

As heterointerface under [110] uniaxial compression. Analysis performed in the frame of hole-hole scattering between carriers in the two spin splitted subbands of the ground heavy hole state indicates, that h-h scattering is strongly suppressed by uniaxial compression. The decay time

Thermally activated negative photoconductivity below 6 K in p-GaAs/Al0.5Ga0.5As heterostructures and the effect of uniaxial compression

\tau_{01}

Magnetotransport effects in p-GaAs/AlGaAs quantized structures under uniaxial stress

of the relative momentum reveals 4.5 times increase at a uniaxial compression of 1.3 kbar.

The Semiconductor‐Semimetal Transition in Bi1−xSbx Alloys

Uniaxial compression of the p-type GaAs/Al0.5Ga0.5 As heterostructures induces magnetic breakdown between the spin-split ground-state subbands of two-dimensional heavy holes. This phenomenon serves as direct experimental evidence of a strong qualitative modification of the energy spectrum of these structures upon uniaxial deformation. This modification has been revealed by numerical calculations, and, according to it, the subband spin splitting decreases upon compression, while the contours of the hole Fermi surface in both subbands touch one another in the compression direction in a pressure range of 2.5 kbar.