Highly fluorescent silver nanoparticles (Ag-NPs), soluble in a ferroelectric host of polymer molecules such as poly(vinylidene fluoride(PVF2), have been created in the form of nanofluids. The content of Ag-NPs (flocculates)is varied in steps 0.1–0.2 wt% up to a value of 5.0 wt% in tailoring a broad green emission band over 520–620nm out of a hybrid percolation Ag–PVF2 composite. A maximum intensity arises in this band at as small a percolation threshold as 0.1wt% Ag-NPs. It contains three distinct bands of peak values 541, 565, and 582nm in an Ag-NPs tunable response of the localized surface plasmons. The emission-dependent anti-Stokes excitation spectrum contains a similar group of three bands 348, 401, and 421 nm. For Ag-contents above 0.1 wt%, interdependent intensities in the emission and excitation bands drop rapidly by as much as five times, conferring a metal–polymer percolation network. The results open wide applications for biological labels and light emitters using such nanofluids.

Построена математическая модель процесса формирования высокого внутреннего расклинивающего давления в наноструктурах для различных геометрий строения. Исследованы особенности влияния физико-химических факторов на это давления. A mathematical model of the process of forming a high internal wedging pressure in the nanostruc-tures for different geometries of the structure is built. The peculiarities of physicochemical factors influ-ence on this pressure are investigated.

Stoichiometric and nitrogen doped SiC nanopowders have been investigated by multi-approaches EPR methods. The paramagnetic intrinsic defects formed in the nanoparticles were studied by cw EPR, field swept electron spin echo, pulsed electron nuclear double resonance and hyperfine sublevel correlation spectroscopy.We observe weak 29Si and 13C superhyperfine couplings with silicon and carbon atoms in the second coordination sphere and beyond indicating a high delocalization of the electronic wave function of the unpaired electron. Additional coupling with protons from presumably clustered hydrogen atoms have been detected. Although nitrogen has been found to be present in the nanomaterials no related shallow donor state was formed.

The intra-Landau-level excitations of the two-dimensional electron–hole liquid are characterized by two branches of the energy spectrum. The acoustical plasmon branch with in-phase oscillations of electrons and holes has a linear dispersion law in the range of small wavevectors, with a velocity which does not depend on the magnetic field strength, and monotonically increases with saturation at higher values of the wavevectors. The optical plasmon branch with oscillations of electrons and holes in opposite phases has a quadratic dependence in the range of long wavelength, a weak roton-type behaviour at the intermediary values of the wavevectors and monotonically increases with saturation similar to the case of the acoustical branch. The influence of the supplementary in-plane electric field leads to the drift of the charged particles in the crossed electric and magnetic fields and to the energy spectrum as in the reference frame, where the e–h system is moving with the drift velocity. A perturbation theory using the Green function method is developed on the basis of a small parameter v^2(1−v^2), where v^2 is the filling factor and (1−v^2) displays the phase space filling effect.
J. Phys.: Condens. Matter 21 (2009) 235801 (9pp)