The magnetic field dependence of the magnetoresistance in nondegenerate n-Ge is experimentally and theoretically investigated. The conductivity component connected with the impurity scattering (uiY) is selected. Its magnetic field dependence in quantizing magnetic field is in accordance with theory.Es wird die Abhangigkeit des Magnetowiderstandes vom Magnetfeld fur nichtentartetes, n-leitendes Ge experimentell und theoretisch untersucht. Die mit Storstellenstreuung verkniipfte Leitfahigkeitskomponente (ubg) wird getrennt bestimmt. Ihre Abhkngigkeit vom Magnetfeld im quantisierenden Magnetfeld befindet sich in Ubereinstimmung mit der Theorie.

The isotropic scattering of current carriers is investigated in quantizing magnetic fields a t arbitrary value of the action radius of the scattering centre. A variational method is suggested allowing to obtain the phase functions of scattefed electron, by means of which the electroconductivity is calculated. A comparison is made with earlier works, which are valid for the short-range forces. In semiconductors, as a rule, the case of an intermediate action radius of scattering centre is found. It is shown, that in the case of short-range forces the known results are received in first approximation. Numerical calculations are made for the parameters of GaAs.

[loo] a r e also shown. As evidenced by these data, the magnetoresistance of I the relatively weakly doped crystals (curves 1 and 1 of Fig. 1) is essentially anisotropic in the investigated H interval. + +The lack of quantitative agreement between experimental and theoretical results was noted before in (2) a s caused by the fact that the used interval of magnetic fields and concentrations i s at the applicability limit of the theory (or even beyond), which is determined by the inequality r << 1 (where r is the screening radius and 0 0

P. I. BARANSKI et al.: Conductivity of an Electronic Gas 359 phys. stat. sol. (b) 71, 359 (1975) Subject classification: 14.3; 22.1.1 Institute of Semicondwtmq Academy of Sciences of the Ukrainian SSR, Kiev ( a ) and State Unirersity of Chernovlsy ( b )The anisotropic impurity scattering of current carriers has been studied in quantizing magnetic fields for n-Ge type semiconductors. General expressions for t,he conductivity for the cases of nondegenerate and degenerate electronic gas were obtained. The formulae for the mobility in the quantum limit for these two cases were analysed and a physical interpretation of the obtained results is given. HccnenyeTcH a~m o~p o n~o e paccemiue HocuTenei3 ToKa Ha npuMecearx noHax B KBaHTyloUMX MarHUTHblX nO.rlRX B IIOnynpOBOAHHKaX Tuna n-Ge. nOnyqeHhl 06uue BbIpaHteHHH AnJi IlpOBOnHMOCTU B CJlylrae HeBbIPOHiAeHHOrO H BblpOHcAeH-HOrO WIeKTPOHHOrO ra38. npOaHaJlH3HpOBaHbI @OpMyJlbI AJIH KIOABHWHOCTK B KBBH-TOBOM npenene 2.m TUX nByx cnylraeB H AaHa cpusuqec~a~ mTepnpeTaum nony-4eHHblX PeayJlbTaTOB.

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