[en] The viscous dragging of dislocations in CsI, NaCl, and LiF crystals in the temperature range of 77 to 293 K is studied on the basis of experimental and theoretical investigations of the shock deformation kinetics in crystalline rods. The dynamics of dislocations in NaCl and LiF crystals deformed by ultrashort pressure pulses produced by an electron beam is investigated. (author)

[en] When studying magnetostimulated dislocational mobility in LiF crystals new features of the dependence of dislocations mean path l on magnetic field B were revealed. Transition from conventional proportionality l ∝ B² to saturation l ∼ const at high fields of B was found. It is shown that experimental points are described in a satisfactory manner by theoretical dependence l ∝ [(B₀/B)² + 1]^-1 (B₀ ∼ 0.8 Tl) typical of the mechanisms of spin longitudinal relaxation in the system of radical pairs. In line with the theory the level of B₀ field is determined by characteristic oscillation frequencies of internal fields in the lattice, which at B₀ ≅ 1 Tl proved 10¹¹ s^-1

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[en] Impact of low doses of X-ray radiation on magnetoplastic effect is alkali-halide crystals, consisting in detachment of dislocations from paramagnetic centers under effect of external magnetic field is studied. The measurements of LiF crystals and three types of NaCl crystals, differing in the admixture content were conducted. Dependence of the dislocations medium run on the sample rotation frequency in the magnetic field proved to be especially sensitive to low doses

[en] The paper introduces a new way to investigate into the effect of X-ray irradiation on the spectrum of point defects in crystals. The measured dependences of the average range of dislocations on the frequency of specimen rotation in the magnetic field represent the bulk of the information. The conducted studies using NaCl crystals have demonstrated the unique sensitivity of this technique to low doses of irradiation (starting from 10³ rad). It turned out that the measured frequency dependences of the dislocation ranges response both to the variation of the states of the present impurity centres and to the formation of Eigen radiation defects. 35 refs., 5 figs

[en] The effect of combined action of mechanical electromagnetic pulses, generated by electron beam, on the motion of the edge dislocations in the NaCl crystals is studied. The methodology of experiments is described in detail. Dependences of the dislocations average run length in the NaCl crystals on the magnetic field induction and electron beam current in absence of mechanical impact and by summarized action of the mechanical and electromagnetic fields are presented. The dependence of the run-length on the pressure mechanical pulses is obtained by deduction from the summarized run lengths of those runs, which were conditioned by the electromagnetic field. Good agreement of the experimental and calculational data indicates the additivity of mechanical and electromagnetic effects. The calculated coefficient of the dynamic breaking of the edge dislocations equals ∼ 2x10^-4

[en] A new physical phenomenon - magnetoplastic effect lying in shifting of dislocations under the influence of permanent magnetic field at the absence of mechanical load is detected and studied for some non-magnetic monocrystals (NaCl, LiF, CsI, Zn and Al). Experiments are carried out in B=0.1-2 T magnetic fields within T= 4.2-293 K range. Main properties of the observed effect enabling to introduce a hypothesis about its nature, are determined. 14 refs., 9 figs

[en] Peculiarities of crystal deformation at shock (impact) loading are studied. The character of variation of the pulse value and shape along the sample is investigated. Dynamic braking of edge dislocations in CsI crystals with different concentration of anion impurities and thallium impurity is investigated on the basis of the new method of experimental data processing which does not use the model assumptions of the shape and duration of the pulse of tension. It is shown that in the 77-293 K temperature range the coefficient of viscous braking grows linearly with temperature. The anion impurities and thallium impurity at the concentrations used do not affect within the limits of the experimental error on the absolute value and temperature run of the viscous braking coefficient. The indication of transformation to the viscous regime of dislocation motion is yield to linearity of the dislocation path dependence on the distance to the free face plane. The dislocation braking coefficient is directly determined according to the dependence slope. Besides, in the process of measurements it should be taken into account the possibility of continuation of clastic vibrations in the sample after its resilience, as it occurred in some realizations of our experiments, and also residual sample deformation

No abstract available