An anodic alumina membrane is produced in two levels by performing the anodization process in various type of acidic electrolyte. Holes are characterized by hexagonal structure of varying diameters (from 40 to 420 nm). The heat and chemical stability as well as the regularity of the formed holes make the membranes appropriate for use in gas separating process, drug delivery and for fuel cell membrane applications. Detachment of the membrane from the aluminum base is the most important step in the membrane production process. In this research, initially, the synthesis of the aluminum based layer omitted the use of CuSO₄ and HCl. In the second step, the barrier layer at the end of the holes was removed via treatment with an aqueous phosphoric acid solution. The aim of this work is to analyze the effect of time upon the barrier layer removal process and, assuming that we have added gold to the alumina membrane, i.e. the alumina membrane has its empty pores filled with gold, simulations were done in order investigate its absorption spectra. Simulations were done using the FDTD method for all structures evaluated. The values for the structures’ absorption and their spectra were calculated and plotted. In the case when the aluminum membrane pores are filled with gold, the curve of gold absorption spectrum has the highest absorption, so in practical terms, this means that making this membrane can have different applications.

   We studied the mechanism for the formation of cerium-activated barium fluoride scintillation ceramics and especially X-ray luminescence of its powdered precursors, prepared by co-precipitation of barium and cerium fluorides from aqueous solutions. We have found that the Ce³⁺ luminescence, which is typical for cerium (III)-containing ceramics and single crystals, was not observed for such polycrystalline precursors, and the intensity of barium fluoride’s own luminescence decreases with increasing amounts of the cerium dopant in the specimens. We have interpreted our results as two-phase precipitation of barium hydrofluoride (BaF₂·HF) and cerium fluoride, respectively. Cerium (III) became incorporated in fluorite-type barium fluoride lattice only later, in the course of ceramics synthesis by the hot-pressing technique.

   Implementation of the multiple impurity, noncollinear Alexander-Anderson model is described in detail and an analytical expression given for the force which determines the orientation of the magnetic momenta as well as a corresponding magnetic force theorem. Applications to trimers of Cr, Mn and Fe adsorbed on a metal surface are described, including the energy surface as a function of the the angles specifying the orientation of the magnetic momenta and minimum energy paths for transitions between stable states, which necessarily involve noncollinear ordering. A simple model for the interaction of a magnetic STM tip with a Cr dimer on a surface is briefly described. A finite range approximation is also formulated, which simplifies the self-consistency calculations and results in linear scaling of the computational effort with the number of magnetic atoms in the system. The theoretical approach described here can be used to study magnetic systems with complex energy landscapes, including stable states and magnetic transitions in frustrated magnetic systems, over a range in length scale, from a few to several thousands of magnetic atoms.

   The article presents the results of an experimental study of the effect of the radiofrequency radiation (RF) of a cell phone on a freely suspended liquid-crystal film (FSLCF) as a system that simulates biological structures. The selection of the FSLCF model is theoretically substantiated. A polarizing microscope with a video camera was used to visualize the process under study. The reaction of the FSLCF was analyzed using a specially developed software. The responses of the FSLCF were studied for exposure to the RF radiation in the presence of protective device Gamma 7.N-RT and for the action of a static magnetic field of strength 500 Oe. The RF radiation of a cell phone was found to change the orientation structure of the FSLCF, which, after some time, returns to the nearly initial level despite the presence of external field. The protective device Gamma 7.N-RT attenuates the reaction of the FSLCF. The response of the FSLCF in a static magnetic field remains unchanged during the exposure to the field. These experimental results are evidence that the structure of the freely suspended liquid-crystal film is a viable model for biological structures, and is capable of adapting to the effect of the RF radiation emitted by a cell phone.

   Thin films and nanorods of Sn_1-xPb_xS (0.00 ⩽ x ⩽ 0.45) with orthorhombic crystal structure and c-axis oriented perpendicular to the substrate surface were grown by hot wall vacuum deposition (HWVD) method. The nanorods grew via a self consuming vapor–liquid–solid (VLS) mechanism by means of Sn-droplets onto the surface of an underlying thin film. The former one consists of stacked blocks with their c-axis always parallel to the growth direction. However, each block is alternately rotated around the [001] against its underlying and subsequent one. As revealed by composition analysis, there is no composition gradient across or within the nanorods and the underlying film. The rods were about 500 nm high and 250 nm in diameter. The droplet at the top of rods consists of Sn with small trace of Pb and S. The density of rods, arranged like a lawn, depends on the metal ratio and substrate temperature. The as-grown Sn_1-xPb_xS samples showed p-type electrical conductivity. Increasing the lead atom concentration results in a decreased Seebeck coefficient and lower conductivity.

   Semiconductor ZnCdS nanowire arrays have been synthesized by electrochemical deposition from aqueous solutions into porous anodic alumina substrates. X-ray diffraction analyses show that the as-synthesized nanowires have a highly preferential orientation. Scanning electron microscopy indicates that high-filling, ordered, and single-crystalline nanowire arrays have been obtained. The optical absorption spectra of the nanowire arrays show that the optical absorption band edge of the ZnCdS nanowire array exhibits a blue shift compared with that of bulk ZnCdS. The growth mechanism and the electrochemical deposition process are discussed together with the chemical compositions analysis.

   In this work, the absorption of aluminum nanoparticles and the critical energy densities of the pentaerythritol tetranitrate-aluminum nanosystems, initiated by laser pulses, were calculated for wavelengths from 400 to 1200 nm. Data showed that it is necessary to consider both thermal and optical characteristics in order to calculate the critical initiation energy density and the radius of the most dangerous inclusion. The nanoparticle’s radius, corresponding to the maximum on the curve of absorptivities, and the maximum’s amplitude and critical energy density of the explosive materials, were all shown to depend on the initiating wavelength. The maximum of the aluminum nanoparticles’ absorptivity and minimum of the critical energy density of the explosive decomposition were observed for the 400 nm wavelength, there is also a local maximum at 850 nm. The results from the experiment qualitatively and quantitatively agree with our calculations. These results are very important to optimize the cap composition for the optical detonators.

   Measurement of local quantum yields for the photoluminescence of semiconductor nanocrystals (quantum dots) and photoinduced transformations of dye molecules in polymer films is demonstrated using a laser scanning microscope capable of mapping luminescence spectra and intensities of transmitted laser light. The confocal scanning microscope (Zeiss LSM710) was applied for both the induction of photochemical transformations and measurement The luminescence quantum yield values for quantum dots in different locations of a polymer film were found to differ, ostensibly depending on their aggregation. To measure photoisomerization quantum yield, the effects of scanning a tiny area of a polymer film with a focused beam on the intensities of luminescence and transmitted light were monitored.

   Practical methods for hydrogen storage are still a prime challenge in the realization of an energy economy based on Hydrogen. Metal organic frameworks (MOFs) are crystalline ultra-porous materials with ability to trap and store voluminous amounts of gas molecules. MOFs represent an encouraging storage method relying on their enormous surface area. However, MOFs show reduced hydrogen uptake at room temperature due to low adsorption energy of hydrogen. To increase the adsorption uptake of MOFs at room temperature, the adsorption energy must be increased. In this contribution, materials exhibiting higher adsorption energy and enhanced hydrogen adsorption, namely MIL-53 (Al) and MOF-74, have been investigated using molecular dynamics (MD) simulation. MD simulations were performed within the density functional based tight binding method (DC-SCC-DFTB). Our results demonstrate that DC-SCC-DFTB method predicts structural parameters, adsorption sites, adsorption energies and diffusion factors with a very good accuracy, making this method a very powerful tool to investigate various types of MOF. Moreover, results show that the adsorption energy can be increased by incorporation of transition metals in MOF structures.

   A novel entry toward poly( 2,6-diimidazo(4,5-b: 4’,5’-e)pyridinylene-1,4(2,5-dihydroxy)-phenylene) (PIPD) has been elaborated. A strategy based on a new route to monomers: a sequential nitration of 2,6-diaminopyridine with KNO₃/H₂SO₄ gives 2,6-diamino- 3,5-dinitro pyridine (DNDAP) in moderate yield and its hydrogenation with Raney nickel as catalyst leads to 2,3,5,6-tetraaminopyridine (TAP) in high yield. The second monomer 2,5-dihydroxyterephthalate (DHTA) was synthesized in high yield as product of sulfur-mediated aromatization of dimethyl succinoyl succinate with subsequent base hydrolysis. PIPD was synthesized by step-by-step heating in polyphosphoric acid with molecular weights of 19 – 25 kilodaltons. The macromolecule of PIPD can be seen as lap-join chain form nano-sized rigid fragment. The as-polymerized liquid crystalline PIPD solution was used for fiber spinning. The tensile strength of PIPD fibers were 1.28 – 1.99 GPa and depended on the molecular weight of the polymer used for spinning.

   Distinctive features of dielectric properties of a ceramic material based on Aurivillius phase Bi₁₀Fe₆Ti₃O₃₀ have been studied.

   Lanthanum fluoride (LaF₃) was synthesized using LaCl3 and NH₄F as starting materials in de-ionized water as solvent via a microwave-assisted technique. The structure of LaF₃ nanocrystals, analyzed by XRD and TEM, was found to be hexagonal with an average crystalline particle size of 20 nm (JCPDS standard card (32-0483) of pure hexagonal LaF₃ crystals). The resistivity and conductivity at room temperature for LaF₃ was verified and found to depend on the applied DC field. At an applied voltage of 20 V/cm – 30 V/cm, the resistivity and conductivity changes rapidly due to the liberation of extra fluoride (F⁻) ions, whereas the conductivity of LaF₃ nanocrystals depends upon temperature. The variation of dielectric constant (ε′) and dielectric loss (ε′′) with applied frequency shows normal dielectric behavior, attributable to the space charge formation. The observed peak in the plot of tangent loss (tan δ) vs. log F around 2.6 KHz can be attributed to interface charge relaxation at the grain boundaries.

   Specific features of the structure of nanoporous carbon, prepared by chlorinating silicon carbide nanoparticles followed by treatment thereof by hydrogenation have been studied. A considerable number of microscopic pores in carbon nanoparticles have been shown.

   Nanocrystalline LnFeO₃ (Ln = La, Gd) ferrites have been prepared by the co-precipitation method followed by heat treatment in air. The formation mechanisms for LaFeO₃ and GdFeO₃ in Ln₂O₃ – Fe₂O₃ – H₂O (Ln = La, Gd) systems under the mentioned conditions are investigated. The phase interaction scheme, reflecting ways which lead to the target, synthesis product yield, as well as the common tendency of LaFeO₃ and GdFeO₃ formation mechanisms, are constructed. The mean sizes of coherent scattering regions of LaFeO₃ and GdFeO₃ were determined to be 30 ± 3 and 40 ± 4 nm, respectively.