LOW-TEMPERATURE NEGATIVE MAGNETORESISTANCE IN THE DELTA-DOPED BY SN AND SI ON VICINAL AND SINGULAR SUBSTRATES GAAS STRUCTURES

The anisotropy of conductivity and negative longitudinal and perpendic ular magnetoresistance in GaAs delta-doped by Sn and Si on vicinal and singular surface structures was investigated in the temperature range 0.4K<T<100K in magnetic fields B<8T. On a GaAs(Cr) substrate inclined at a small angle theta-0.3 degrees from (001) plane to (110) plane wi th help of MBE GaAs(delta-Sn) or GaAs(delta-Si) structures were synthe sised. The anisotropy of conductivity and NM is higher for GaAs(delta- Sn) structures on vicinal substrate. In parallel magnetic field one of the reason of the negative magnetoresistance is the 2D scattering. Ma king use the theory of the NM the parameters of 2D electrons were dete rmined.