Experimental device for study of the thermal stimulated direct current in the composite materials.

Presents the device for analysis the thermally stimulated electrical conductivity of composites in the wide temperature range. The main advantage of the module in relation to those described earlier is that it allows experiments both in the mode of measuring the current of thermally stimulated depolarization (TSDC) at low temperatures, and in the mode of measuring the thermally stimulated conductivity current (TSCC) up to very high temperatures. Using PMMA/PVDF mixtures as an example, it is shown that the TSDC method can be used to temperature transitions analysis in the many composite materials at low temperatures.

"Awakening" of the S Emission of Tricarbocyanine Dyes Stimulated by Interaction with Carbon Quantum Dots.

Anti-Kasha emission (i.e., the emission from S ( > 1) excited levels) of infrared chromophores which possess intensive absorption and S emission in the near-infrared region, but which are spectrally silent in the visible, is a challenging task for relevant applications such as energy conversion, bioimaging, sensitization of solar cells, optical sensors, and so on.

Excimer Emission in J-Aggregates.

An excimer in J-aggregates has been often considered as a self-trapped exciton originating from the free exciton excited on the same aggregate and relaxed through interaction with vibronic modes. Here we show that other types of excimers due to intermolecular off-diagonal interactions can be observed in J-aggregates of thiamonomethinecyanine dyes. These excimers arise owing to free excitons too, but they possess a longer formation time of more than 100 ps, indicating migration of free excitons to the excimer formation site, where they interact with a guest species in the ground state.

Renormalization of the critical exponent for the shear modulus of magnetoactive elastomers.

It is shown that the critical exponent for the effective shear modulus of a composite medium where a compliant polymer matrix is filled with ferromagnetic particles may significantly depend on the external magnetic field. The physical consequence of this dependence is the critical behavior of the relative magnetorheological effect.

Effect of single-particle magnetostriction on the shear modulus of compliant magnetoactive elastomers.

The influence of an external magnetic field on the static shear strain and the effective shear modulus of a magnetoactive elastomer (MAE) is studied theoretically in the framework of a recently introduced approach to the single-particle magnetostriction mechanism [V. M. Kalita et al.

Impact of Water Adsorption on Nonlinear Optical Properties of Functionalized Porous Silicon.

The porous silicon (PS) surface modification diagnostics due to functionalization and water adsorption/desorption processes were provided by the self-action effects of picosecond range pulsed laser radiation at 1064 nm. It was shown that the PS surface functionalization-oxide removal, alkylation, and oxidation-resulted in a refractive nonlinear optical (NLO) response sign turn to self-focusing (Δn>0) versus the self-defocusing (Δn<0) observed in the aged PS. The sensitivity of the proposed technique was revealed to water adsorption/desorption from the chemically oxidized PS interface.

Single-particle mechanism of magnetostriction in magnetoactive elastomers.

Magnetoactive elastomers (MAEs) are composite materials comprised of micrometer-sized ferromagnetic particles in a nonmagnetic elastomer matrix. A single-particle mechanism of magnetostriction in MAEs, assuming the rotation of a soft magnetic, mechanically rigid particle with uniaxial magnetic anisotropy in magnetic fields is identified and considered theoretically within the framework of an alternative model. In this mechanism, the total magnetic anisotropy energy of the filling particles in the matrix is the sum over single particles.

Photoinduced refractive index variation within picosecond laser pulses excitation as the indicator of oxyorthosilicates single crystals composition modification.

For the first time, the diagnostics of oxyorthosilicates single crystals based on self-action of picosecond range laser pulses at 1,064 nm (1.17 eV) has been performed. High sensitivity of the photoinduced refractive index variation to the substitution of the Lu atoms by Gd in the LSO/LGSO crystalline host as well as to the admixture of Ce was found.

Electrostatic plasma lens for focusing negatively charged particle beams.

We describe the current status of ongoing research and development of the electrostatic plasma lens for focusing and manipulating intense negatively charged particle beams, electrons, and negative ions. The physical principle of this kind of plasma lens is based on magnetic isolation electrons providing creation of a dynamical positive space charge cloud in shortly restricted volume propagating beam. Here, the new results of experimental investigations and computer simulations of wide-aperture, intense electron beam focusing by plasma lens with positive space charge cloud produced due to the cylindrical anode layer accelerator creating a positive ion stream towards an axis system is presented.

Recent advances in plasma devices based on plasma lens configuration for manipulating high-current heavy ion beams.

We describe new results of development of novel generation cylindrical plasma devices based on the electrostatic plasma lens configuration and concept of electrons magnetic insulation. The crossed electric and magnetic fields plasma lens configuration provides us with the attractive and suitable method for establishing a stable plasma discharge at low pressure. Using plasma lens configuration in this way some cost-effective plasma devices were developed for ion treatment and deposition of exotic coatings and the effective lens was first proposed for manipulating high-current beams of negatively charged particles.