[en] Ferroelectric solutions Pb(Tisub(x)Zrsub(1-x))Osub(3) when Ti content constitutes 30, 35, 40, 44 and 50% in the range of hydrostatic pressures up to 40 kbar and quasihydrostatic pressures up to 80 kbar in the temperature range from +20 to +150 deg C have been studied. Measurements of dielectric permeability (epsilon) and spontaneous polarization (Ps) depending on pressure at different constant temperatures from +20 to +150 deg C are made. The detected anomalies of epsilon and Psub(s) are explained in the framework of physical notions on domain reorientations under pressure. For all the compositions studied phase p-T-diagrams are built, coordinates of ternary points detected are found, the coefficients are dT/dp. An untiferroelectric phase, existing under conditions of high pressures above 30 kbar for solid solutions Pb(TiZr)O₃ with Ti content above 30% is detected. Spatial diagram ''composition-pressure-temperature'' is plotted

[en] Dose and temperature dependences of anion defect accumulation in MgO crystals irradiated with protons have been investigated. It is shown that under high ionizing irradiation of MgO non- shock generations of Frenkel anion pairs is possible. The nonshock generation of anion defects is related to radiationless decay of complex electron excitations arising in proton tracks

[en] The temperature dependence of T₁ spin-lattice relaxation time on ⁵¹V, ⁶⁹Ga, ⁷¹Ga and Knight shift on ⁵¹V and ²⁹Si nuclei in polycrystalline V₃Si, V₃Ga, V₃Ge and in the monocrystal V₃Si in normal state is investigated. For V₃Si and V₃Ga a rapid growth (T₁T)^-1 is observed with temperature decrease while for V₃Ge the maximum (T₁T)^-1 at T approximately equal to 60 K has been found. The temperature dependence peculiarities have been discussed on the basis of theoretical models available and zone structure calculations for A-15 compounds. The T₁ anisotropy and possibility of its experimental discovery are considered. Anisotropic contribution in (T₁T)^-1 and contributions of d states of different symmetries into the electron state density at the Fermi level are estimated for V₃Si from T₁ measurements

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[en] The nonlinear absorption of the CO₂ laser irradiation in indium antimonide is investigated by the method of two orthogonal beams. The calculation is made which explains the technique of calculating constants of two-photon absorption (TPA) from the experimental data. Results of experiments show that a significant contribution in the induced absorption of the ΔI₃ probing beam except TPA and the absorption on nonequilibrium holes created by pumping radiation in the process of TPA is made by the absorption from deep mixture centres changed by the pumping beam. The role of the latter mechanism depends on the moment of measuring ΔI₃ within the limits of laser pulse and on the level of crystal alloying. The increase in the level of alloying leads to the reduction in the contribution of this mechanism. The obtained values of TPA constants for two crystals with different electron concentrations in the conductivity zone (InSbn₀=2.4x10¹⁶cm^-3 and n₀=2.5x10¹⁷cm^-3) which is connected with the alteration of filling states in the conductivity zone

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[en] The results of experimental investigation of magnetic transformation in a hematite monocrystal (α-Fe₂O₃) below Morin point (Tsub(m) approximately equal to 261 K) in a pulse magnetic field are presented. In the course of measuring hematite monocrystal neutron scattering in which the first order phase transformation has been induced by a pulse magnetic field along the ordinary diffraction peaks additional peaks are observed. These peaks are explained by neutron diffraction on new phase small particles. The analysis of the form of peaks allows estimating concentration and particle sizes as well as the velocity of the domain wall movement connected with phase reconstruction. The field values at which additional scattering is observed, considerably differ from the field corresponding to interphase equilibrium. The qualitative explanation of this fact consists in the fact that scattering is due to new phase centres produced in an uniform perfect crystal. Such centres may ap.oear only when sufficiently remoted from the equilibrium state

[en] Transmission of submillimeter waves is measured in the range of 4-50 cm^-1 with monocrystal YFeO₃ plates in the external zero magnetic field. Plates of different thickness and orientations have been used in measurements. Resonance lines of absorption at frequences of 8.7, 35.0 and 45.2 cm^-1 (+-0.3 cm^-1) are found in the YFeO₃ monocrystal transmission spectra. A supposition is made on the connection of the first two lines with antiferromagnetic resonance in YFeO₃ in the zero external magnetic field and of the third line with excitation of optical phonons in perovskite lattice