SCALING IN THE REGIME OF THE QUANTUM HALL-EFFECT AND HOLE LOCALIZATION IN P-GE GE1-XSIX HETEROSTRUCTURES/

For multilayer Ge/Ge1-xSix (x similar or equal to 0.03) heterostructur es with two-dimensional p-type conductivity over the Ge layers, the te mperature and magnetic dependences of the longitudinal resistivity rho (xx) and the Hall resistivity rho(xy) have been studied in fields up t o 12 T in the temperature interval of T=(0.1-15) K. The observed decre ase of the amplitude of the rho(xx) peaks with decreasing temperature for T less than or equal to 2 K corresponds to a transition to the sca ling regime under the conditions of the quantum Hall effect. Scaling d iagrams in the (sigma(xy), sigma(xx)) coordinates have been constructe d for the region of fields and temperatures of interest. It is found t hat, on the whole, the form of the diagrams corresponds to the theoret ical predictions. It is shown that the character of the flux lines on the scaling diagrams is directly connected with such a parameter as th e width of a band of delocalized states at the center of the Landau le vel. (C) 1997 American Institute of Physics.