Piezoresistance of uniaxially deformed along the crystallographic direction [100] single crystals n-Ge for different fixed temperatures has been investigated. Presence of the significant piezoresistance for given conditions of the experiment is explained by increase in the effective mass and decrease in the relaxation time for electrons at the expense of the inversion of (L1-∆1) type of an absolute minimum in n-Ge. Temperature dependencies of resistivity for undeformed (L1model of conduction band) and deformed under uniaxial pressureP=3 GPа (∆1model of conduction band) single crystals n-Ge are obtained. Resistivity for undeformed single crystals n-Ge is changed according to the law ρ~T1.66. Resistivity for uniaxially deformed single crystals n-Ge is changed as ρ~T1.53. The given dependencies show that for L1 model of the conduction band in contrast to ∆1model one must equally with intravalley scattering of electrons on acoustic phonons take into account scattering of electrons on optical and intervalley phonons. Therefore reduction of the magnitude piezoresistance  n-Ge with the increasing temperature is associated with “turning-off” at the expense of the inversion of (L1-Δ1) type of absolute minimum under uniaxial pressure P>2.7 GPа mechanism for scattering of electrons on intervalley and optical phonons. Comparison of results of theoretical calculations with relevant experimental data shows that peculiarities of piezoresistance n-Ge under uniaxial pressures  1.6<P<2.7 GPа for (L1-Δ1) model of conduction  band  n-Ge can be described only taking into account nonequivalent intervalley scattering of electrons between the minima L1 and Δ1.

На основi експериментальних даних поздовжнього п'єзоопору кристалiв n-Ge та теорiй деформацiйного потенцiалу й анiзотропного розсiяння знайдено комбiнацiю констант деформацiйного потенцiалу, ефективну масу густини станiв, компоненти тензора ефективної маси для ∆1-мiнiмуму зони провiдностi кристалiв n-Ge. Показано, що характер екранування i вiдповiдно розсiяння змiнюється при реалiзацiї в кристалах германiю з використанням одновiсного тиску вздовж кристалографiчного напрямку [100] iнверсiї типу (L1 − ∆1) абсолютного мiнiмуму. Це пояснюється рiзними значеннями радiуса екранування й екрануючого множника для L1 та ∆1-мiнiмуму.Ключовi слова: деформацiя, п'єзоопiр, анiзотропiя розсiяння.

Temperature dependencies for Hall mobility of electrons for the uniaxially deformed n-Si single crystals, irradiated by the flow of electrons Ω=1·1017 el./cm2 with the energy of 12 MeV, are obtained on the basis of piezo-Hall effect measurements. From the analysis of these dependencies it follows that under the uniaxial pressure (0–0.42) GPa and (0–0.37) GPa along crystallographic directions [100] and [111], respectively, the deformation-induced increase of the Hall mobility has been observed. On the basis of the proposed theoretical model of mobility, this increase is explained by the decrease of the amplitude of a large-scale potential with an increase in the magnitude of uniaxial deformation and, accordingly, the probability of electron scattering on this potential. The slight discrepancy between the obtained experimental results and the relevant theoretical calculations at the low temperatures is due to the fact that the electron scattering on the radiation defects, created by the electron radiation, was not taken into account in the calculations. The decrease in Hall mobility of electrons along with an increase in temperature for unirradiated and irradiated silicon single crystals is explained by the growth of the probability of electron scattering on the optical phonons that are responsible for the intervalley scattering in silicon. The obtained results can be used in designing and modelling on the basis of n-Si single crystals of various electronic devices of micro- and nanoelectronics, which can be subject to the extreme conditions of action of the significant radiation and deformation fields.

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