Granular films containing Fe₅₀Co₅₀Zr₁₀ alloy nanoparticles inside the ferroelectric matrix Pb_0.81Sr_0.04(Na_0.5Bi_0.5)_0.15(Zr_0.575Ti_0.425)O₃ (PZT) are characterized by a complex of functional magnetic and electrical characteristics that can be effectively controlled by an external electric or magnetic field. The formation of the necessary granular structure in the case of a PZT matrix is possible only during synthesis in an oxygen-containing atmosphere, leading to significant oxidation of metal nanoparticles. In this regard, an urgent task is to study the degree of oxidation of metal nanoparticles depending on the synthesis conditions, as well as the influence of the forming phases on the electrical properties of films.
The relationship of the phase composition and electrical characteristics of granular films (FeCoZr)_x(PZT)_100-x (30 ≤ x ≤ 85, at.%) obtained in an oxygen-containing atmosphere at a pressure of PO in the range (2.4—5.0) ⋅ 10^-3 Pa was studied by X-ray diffraction analysis, EXAFS spectroscopy (Extended X-ray Absorption Fine Structure) and four-probe electrical resistivity measurements.
A comparative complex analysis of the structural-phase composition and local atomic order in films (FeCoZr)_x(PZT)_100-x for the first time showed the fundamental influence of oxygen pressure during synthesis on the oxidation of nanoparticles and their phase composition. It is shown that in the case of oxygen pressure up to the values of P_O = 3.2 ⋅ 10^-3 Pa, a transition from nanoparticles of complex Fe(Co,Zr) oxides occurs with increasing x to the superposition of complex oxides and ferromagnetic nanoparticles α-FeCo(Zr,O) (or their agglomerations). At a higher oxygen pressure P_O = 5.0 ⋅ 10^-3 Pa, complete oxidation of nanoparticles is observed with the formation of a complex oxide (Fe_xCo_1-x)_1-δO with a wustite structure.
The observed structural-phase composition allows us to explain the measured temperature dependences of the electrical resistance of granular films, characterized by a negative temperature coefficient of electrical resistance (TKR) in the entire range of film compositions at high oxygen pressure (P_O = 5.0 ⋅ 10^-3 Pa), and the transition to positive TKR at lower oxygen pressure (P_O = 3.2 ⋅ 10^-3 Pa) in the synthesis atmosphere and the value x ≤ 69 at.% in films. The transition from negative to positive TKR, indicating the presence of a metallic contribution to conductivity, is fully correlated with the detection by XRD and EXAFS methods of non-oxidized ferromagnetic nanoparticles α-FeCo(Zr,O) or their agglomerations.

A theoretical model has been developed for determining free electron concentration in n-InAs from characteristic points in far infrared region of reflection spectra. We show that when determining free electron concentration one should take into account the plasmon-phonon coupling, otherwise free electron concentration will be overestimated. We have calculated electron concentration, N_opt, as a function of characteristic wave number, ν₊, which is described by a third order polynomial. 
Twenty one n-InAs samples (5-doped with tin and 16-doped with sulfur) have been tested at room temperature for electron concentration using two methods, i.e., the conventional four-probe (Van der Pau) method (N_Hall) and the optical method developed by us (N_opt). The reflective surfaces of investigated samples were processed either with chemical-mechanical polishing or treating with short-grained abrasive powder.  
It was shown that for all the investigated samples the condition N_opt > N_Hall was relevant. The difference between optical and electrophysical electron concentration values has been shown to be greater in case of chemically polished reflective surface of the sample and smaller in case of abrasive-treated one. 
The experimental results have been compared with the same data previously obtained for n-GaAs samples. Qualitative model has been suggested to explain obtained experimental data. 

The paper presents the results of studies of the structure, piezoelectric and dielectric properties of lead zirconate-titanate ceramics modified with lanthanum of various concentrations (PLZT). It was found that with an increase in the La content, the grain size and the average domain size increase. The PLZT 12/40/60 samples contain both labyrinth-like and periodic domains, as well as different lateral sizes from several hundred nanometers to 3 microns in diameter. It was found that the piezoelectric response signal increases with increasing domain sizes in samples with a high lanthanum content. The fact of the existence of areas on surface of PLZT x/40/60 ceramics having an internal displacement field is established, as evidenced by the asymmetry of the remnant piezoelectric hysteresis loops along the voltage axis. 
In the samples PLZT 5/40/60 and PLZT 12/40/60, a significant dispersion of the permittivity ε(f) and a maximum of the tangent of the dielectric loss angle were observed in the frequency range from 10⁵ to 10⁶ Hz. This is due to the presence of ionic relaxation polarization, as is the case in ionic dielectrics. It is established that the value of the dielectric constant increases markedly with increasing La, which confirms the occurrence of a rigid unipolar state in the PLZT 12/40/60 ceramic grains. In the samples under study, an increase in the tangent of the dielectric loss angle is observed at low frequencies of the measuring field, which is associated with the contribution of conductivity to tg δ. The dependences of the dielectric loss factor ε” on the dielectric permittivity ε’are constructed. They have the form of Cole-Cole diagrams, which indicates the presence of a relaxation time spectrum, while it was found that the spectrum width in PLZT 5/40/60 samples is about two times less than in PLZT 12/40/60 samples.

The flow structure and mass transfer in crystallizers determine the level of salt supersaturation of the solution near the crystallization surface. However, experimental determination of such supersaturation is difficult. Therefore, it is important to develop adequate numerical models for studying the flow and mass transfer in real molds. Simulation tools were used to study the effectiveness of fundamentally new experimental schemes of the process for the stable growth of KDP crystals.

Magnetic nanoparticles play an important role in rapidly developing advanced branches of science and industry, e.g. fabrication of magnetic storage media, synthesis of ferromagnetic liquids, medicine and chemistry. One problem faced in the usage of magnetic nanoparticles is their high chemical activity leading to oxidation in air and agglomeration. The chemical activity of magnetic nanoparticles stems from the contribution of their large specific surface to volume ratio. Carbon coating of nanoparticles reduces the interaction between nanoparticles. FeCoAl/C metal-carbon nanocomposites have been synthesized using IR pyrolysis of polymer / metal salt precursors. The effect of synthesis temperature (IR heating) in the range from 500 to 700 °C on the structure and composition of the nanomaterials has been studied. We show that the forming particles are the FeCoAl ternary solid solution with a FeCo based bcc lattice. An increase in the synthesis temperature from 500 to 700 °C leads to an increase in the coherent scattering region of three-component nanoparticles from 5 to 19 nm. An increase in the aluminum content from 20 to 30 % relative to Fe and Co results in an increase in the size of the nanoparticles to 15 nm but this also entails the formation of a Co based solid solution having an fcc lattice. An increase in the nanocomposite synthesis temperature and a growth of the relative Al content as a result of a more complete carbonization and the structure-building effect of metals reduce the degree of amorphousness of the nanocomposite carbon matrix and lead to the formation of graphite-like phase crystallites having an ordered structure. The effect of synthesis temperature and relative content of metals on the electromagnetic properties (complex dielectric and magnetic permeability) of the synthesized nanocomposites has been studied. Synthesis conditions affect the radio absorption properties of the nanocomposites, e.g. reflection loss (RL) in the 3—13 GHz range.

At present, all over the world there is a tendency to increase the diameters of single crystals of both elementary semiconductors and semiconductor compounds. There are reports indicating the use of single crystals of III-V semiconductors with a diameter of four to six inches. So far, indium antimonide single crystals up to 75 mm in diameter have been obtained in Russia.
Indium antimonide is the element base of the broadest field of solid-state electronics — optoelectronics. On its basis, linear and matrix photodetectors are manufactured, operating in the spectral wavelength range of 3-5 microns, which are used as a viewing element in thermal imaging systems.
In this work, we selected the thermal growth conditions and obtained indium antimonide single crystals 100 mm in diameter in the crystallographic direction [100]. The solution of this problem has made it possible to significantly increase the yield of suitable photodetectors.
Single crystals 100 mm in diameter were grown by the Czochralski method in a two-stage process. The design of the graphite heating unit was enlarged and matched to a working crucible with a diameter of 150 millimeters and a load of 4.5-5 kg.
The Van der Pauw method was used to measure the electrical properties of the obtained single crystals, which corresponded to the standard parameters of undoped indium antimonide. Using an optical microscope, the etching pits were counted using the 9-field method. The dislocation density in crystals with a diameter of 100 mm was ≤ 100 cm^-2 and corresponded to the values ​for crystals of 50 mm.

Lithium niobate (LN) is a ferroelectric material with a wide range of applications in optics and acoustics. Annealing of LN crystals in an oxygen-free environment leads to the appearance of black coloration and the concomitant increase in electrical conductivity due to chemical reduction. The literature presents many works on the study of the electrophysical properties of reduced crystals of LN, however, the contact phenomena arising during the measurement of electrical conductivity, as well as the interaction of the electrode material with the samples under study, are practically ignored. In this paper, the effect of chromium and indium tin oxide (ITO) electrodes on the results of measurements at room temperature of electrophysical parameters of LN samples recovered at 1100 °C is investigated. It was found that significant non-linearities in the voltage characteristics (I-V curve.) at voltages less than 5V do not allow to obtain the correct values of the resistivity of NL. This leads to the need to carry out measurements at higher voltages. By the method of pulse spectroscopy, it is shown that capacitances, including those formed, probably, in the contact areas, have a strong influence on the measurement results. It is shown that the results obtained are adequately described by a model assuming the presence of contactless tanks connected in parallel to the sample’s own capacity. A possible mechanism for the formation of such containers is described, and an assumption is made about the existence of a significant density of electronic states at the “electrode - sample” interface capable of capturing charge carriers, and with increasing annealing time, the concentration of captured carriers increases.

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