The quantum and chemical simulation (HF/MP2, cc-pVDZ basis) of diphenyl-2,2',4,4'-tetraamine (DPTA) molecule properties allows to determine the its thin film pyroelectric properties since hydrogen bonds between molecules in the film are weaker than intramolecular bonds. The study of a DPTA photosensitive pyroelectric film microstructure enables one to assume that the dipole moment of the needle-shaped crystallines densely stacked and extended along a film surface is aligned perpendicularly to the surface. The possibility of the reproduced control for DPTA properties may be used when producing the most effective pyroelectric film for photodetectors in infrared wavelength range.

Keywords: Diphenyl-2,2',4,4'-tetraamine, quantum chemical simulation, pyroelectric material, thin-film structure

Recently, BiFeO3  multiferroics have drawn a great deal of attention due to their superior ferroelectric properties in epitaxial thin film form in comparison to counterpart bulk single crystals or ceramics. In this work we present the results on magnetic properties of multiferroic ultrathin films (30-300 nm) of BiFeO3, (BiLa)FeO3 and  (BiNd)FeO3  obtained by sputtering in transverse high frequency discharge, vacuum laser oblation and metalorganic chemical vapour deposition  on monocrystalline  substrates of (001) SrTiO3, (100) MgO and  (100) Al2O3. The concentration of Bi, La и Nd in dodecahedral sublattices was varied. A novel effect of treatment of multiferroic films in a negative corona discharge has been investigated. It is demonstrated that the magnetisation may be increased by up to 35%  whilst the change in    is not noticeable. This effect does not depend on neither film composition no technological method. 

Keywords: multiferroics, magneto-electric materials, methods of preparation, the films of bismuth ferrite, pseudomorphic structure, magnetic properties, corona discharge

The synthesis of nanocomposite FeNi3/C based on the PAN, FeCl3 · 6H2O and NiCl2 · 6H2O, whereby the first time by the IR heating at 400 ÷ 700 ° C obtained nanocomposite FeNi3/C FeNi3 particle size of 10 to 80 nm are uniformly distributed UM. Using thermodynamic calculations based on the minimization of the Gibbs energy, confirmed the synthesis of nanocomposite FeNi3/C at T=400 ° C reduction of Fe and Ni with H2, produced during the process of carbonization of polyacrylonitrile with infrared heating. Designed as a nano material of the films can be effectively used as a carrier material for a magnetic information recording superdense. Recording density is achieved in such a carrier (85-100) Gb/dyuym2. ​

Keywords: nanocomposite, polyacrylonitrile, infrared heating, recording information, the magnetic properties, the carbon matrix

The coloration centres (CC) in crystals of rear earth gallium garnets (REGG): Gd3Ga5O12 (GGG), Gd3Sc1,6Ga3,4O12 (GSGG) и Nd3Ga5O12 (NGG) obtained by Chohraljskiy method, were investigated by methods of optical spectroscopy and spectral analysis in the wavelength range of 0,2-0,87 microns. In the case of keeping the samples under dark conditions, unstable CC were formed in the crystals of GGG and GSGG. The absorption maxima are at λmax1 = 0,243 m and λmax2 = 0,275 m at concentration of N ~ 1018 cm-3. It is suggested that the observed enlightenment is caused by the recharging of growth defects and occurring the energy levels in the band gap of garnets. It appears that these CC correspond to centres of O- holes, originated from gallium vacancies V3-Ga 3+ in tetrahedral and octahedral nots which form near clusters of [V3-Ga 3+ - V2+O2- ]

Keywords: color centers, rare earth gallium garnets, kristylly, Czochralski method, the crystal lattice

To date, the main method of mass production of advanced functional materials for various purposes is the ceramic technology. In the manufacture of multi-component oxide compounds using of ceramic technology is difficult to achieve high uniformity of chemical composition. For activation of the raw ingredients and make it more uniform use of chemical-tions (co-precipitation of salts or hydroxides, spray drying, Cryochemistry) and physical-tions (mechano-chemical, microwave, ultrasonic) methods. The paper presents the results of work on obtaining Ni-Zn-ferrite 2000NN radiation-thermal sintering. The influence of base composition and alloying additions on the electromagnetic properties of the ferrites. Confirmed the effectiveness of the use of surface-active additives To increase the density of the raw pieces and level parameters. We propose a model that explain schaya efficiency of dopants in the radiation-thermal sintering.

Keywords: Nickel-zinc ferrite, radiation thermal sintering, base composition, alloying additives, permeability

Promising absorbing materials along with a Ni-Zn-ferrites are Mg-Zn-ferrites, as they are also intensively absorbs electromagnetic waves in the frequency range from 50 MHz to 1000 MHz. The main advantage of the Mg-Zn-ferrite is used as an inexpensive raw material magnesium oxide. The paper presents the results of research to improve the efficiency of broadband radio-magnesium-zinc ferrite by increasing the contribution of the dielectric loss. The influence of alloying elements of the atmosphere gas and cooling after the sintering thermal radiation by absorption of electromagnetic waves. Confirmed cooling efficiency of products after sintering in an atmosphere with reduced oxygen partial pressure to increase the dielectric constant. A model is proposed to explain the increase in the dielectric loss ferrite during cooling in a reducing atmosphere.

Keywords: radioabsorbing ferrites, microstructure grain boundaries radio measurement radiation thermal sintering

The spectra of thermally stimulated conduction currents (TSCC) in (TmBi)3(FeGa)5O12:Ca2+ ferrite-garnet films have been investigated with the purpose to reveal electrically active centres. The samples were fabricated by liquid phase epitaxy (LPE) from melt solution on the Gd3Ga5O12substrates with the crystallographic orientation (111) with the use of Bi-containing flux (without Pb). Increasing the concentration of Ca2+ions in the films were realised by increasing the concentration of CaO in the melt solution. The obtained films contained Ca2+ ions from 0,03 f.u to 0,1 f.u. With the help of standard thermoactivation current spectroscopy the spectra of the initial samples and samples subjected to ultraviolet radiation and negative corona discharge were obtained. The characteristic parameters of electrically active defects were calculated.

Keywords: thermally induced electrical current, ferrite garnet films, electrically active centres, deep-level capture, charge compensation, Ca- doping, ТСТП-spectra, temperature position