The theoretical investigation of the Fermi surface (FS) and constant-energy one near the Fermi energy of La2−xSrxCuO4 and YBa2Cu3O7 is the aim of this work.

The main problem in developing the composite materials containing Shape Memory Alloy (SMA) actuators is to provide the strength of interface between matrix and SMA. The other important problem is to provide the martensitic transformation with needed parameters and resistance to thermal cycling in the composite material. Application of ultrasonic (US) technologies for obtaining composite materials helps to some extent to solve the above-mentioned problems. The ultrasonic technologies available are the composite materials crystallization in ultrasonic field, simultaneous deformations of composite components by using ultrasound and sintering of powdered/fractured composite mix with high-intensity ultrasound apply to different stages of the process. All these are aimed at obtaining the composites with good functional properties. In the present paper, main attention is paid to the composite materials consisting of the CuAlNi, CuAlMn, CuAlZn and Ni-Ti shape memory alloys and various second component (aluminum, copper and Cu-alloys). Two main achievements have been reached by application of the US vibrations: modification and refinement of the shape memory alloy microstructure; improvement in adhesion of the superelastic/shape memory materials to the metal substrate surface subjected to ultrasonic metallisation.

X-ray photoelectron, emission and absorption spectroscopy have been used to study the electron structure and valence state of new ternary intermetallic compounds, which crystallize in the CeGa2Al2 structure. X-ray emission spectra of M and P elements in CeM2P2 compounds have been investigated and the density of the total and partial electron states in this phase has been calculated within the self-consistent LMTO method. Effective filling numbers of electrons in different bands of components in CeM2P2 compounds have been calculated. X-ray spectra of M and P elements in ternary CeM2P2 (M=Fe, Co, Ni) compounds were obtained at 300 K using a tube spectrometer equipped with an RKD-01 co-ordinate detector.

High-temperature alpha-Fe1-xSi2 phase formation on Si (100) under the action of laser irradiation with the light power-density within the range of (0.8-2.2).10(4) W/cm(2), phase composition of epitaxial layer, its structural perfection, and electrophysical properties are studied. As shown, the low power-density irradiation results in the formation of tetragonal alpha-phase with the in-plane oriented c-axis, while at the maximal densities (2.2.10(4) W/cm(2)), c axis is normal to the silicon surface. In contrast to slowly-cooled bulk alpha-phase, which has a Seebeck coefficient equal to alphaapproximate to10 muV/K and exhibits the metallic conductivity, the rapidly-solidified surface-layer alpha-phase is found to be a narrow-gap semiconductor with a Seebeck coefficient of up to 1050 muV/K and the carrier activation energy of 35 meV. Theoretical analysis of an epitaxial crystallization shows that the alpha-phase formation results from both the rapid directional solidification of Fe-Si melt at the rate of about 2 cm/s and 'kinetic competition' between eutectic phases. Activation energy of non-equilibrium a-phase nucleation is decreasing with reducing laser-pulse duration and concentration of structural vacancies in solidifying crystal phase at the crystal-melt interface.

The discovery of high temperature superconductors (HTS) has led to understanding that, in order to explain and utilize the phenomenon, completely new physical approaches should be introduced at all scales: microscopic, mesoscopic, macroscopic. Leaving first two scales beyond the scope of the present paper we focus in the upper limit of the last one, the study of the magnetic flux dynamics in HTS bulks - the dynamics of the 'compact vortex structures'. New experimental approaches to investigation of HTS bulks using levitation techniques, which have been elaborated during last years to effectively explore the subject, as well as the new fundamental and applied results obtained therefrom are overviewed here.

Investigations of the structure and physical properties of glass-coated Fe-Si-B-Nb-Cu microwires obtained by the Taylor-Ulitovsky technique are carried out. As shown, amorphous state in the microwires is, achieved at, the content of metalloid atoms above 25 at.%. The factors influencing the, degree of non-equilibrity of hardening processes in microwires are as follows: cooling rate, undercooling, and stresses originating in microwires during their formation. Annealing of the amorphous microwires at the temperature 500degreesC (30 min) loads to the formation of nanocrystalline structure, which determines the optimal soft magnetic properties.

The optical and magnetooptical properties of Fe/Si multilayered films (MLF) with a strong antiferromagnetic coupling are investigated. The comparison of the experimental and simulated optical conductivity and equatorial Kerr-effect spectra obtained for the different models of the Fe/Si MLF structure allows to conclude that the actual MLF structure significantly differs from the nominal structure, and that neither semiconductor beta-FeSi2 nor semimetallic epsilon-FeSi can be considered as the spacer layers in the Fe/Si MLF providing for the strong AF coupling. The optical properties of such a spacer revealed from the effective optical response of the MLF strongly support its metallic nature. Comparison of the extracted optical properties of the spacer with those calculated for several silicides by using the first principles shows that the metallic FeSi compound with a CsCl-type structure is spontaneously formed at the interfaces during deposition. For the Fe/Si system with ultrathin Fe and Si sublayers (thinner than 1 nm), our optical data indicate that the structure of the whole MLF is close to the amorphous and semimetallic epsilon-FeSi (or semiconducting beta-FeSi2).

Boron distribution in the zone of laser chemical-thermal treatment of steel 12Cr18Ni10Ti is investigated by the methods of metallographic examination and Auger electron spectroscopy. Experimental data are compared with those obtained by modelling of the mass, transfer and structure formation processes, which develop in a laser microbath. As shown, the structure-concentration picture observed in the borided cases is a result of the crystallization processes, which conform with the specific constitution of the phase diagram describing the 'basic metal-satufant' system state.

The influence of structural disorder on the magnetic, transport, and optical properties of Ni0.50Al0.50 alloy films has been investigated. A significantly disordered state was obtained by using vapor-quenching deposition onto substrates cooled by liquid nitrogen. The loss of translational invariance in the disordered state leads to a prominent increase of the magnetic moment of alloy below 50 K. This growth can be explained by the appearance of antistructure Ni atoms (or their clusters) in the disordered state of alloy and their ferromagnetic coupling below 50 K. The temperature dependences of resistivity for both ordered and disordered states of the Ni0.50Al0.50 alloy films exhibit the resistivity minimum at 17–18 K, which has a nonmagnetic nature and can be related mainly to the quantum corrections to the electron–electron interactions in the presence of weak localization. It was shown that the resistivity of the ordered Ni0.50Al0.50 alloy films in 50–300 K temperature range originates mainly from the electron–phonon scattering, while in the disordered state the contribution from the electron-phonon-vibrating impurity scattering becomes dominant. The structural disordering also leads to a noticeable change in the optical properties of alloy, especially in the infrared region. The observed temperature and structural dependences of the resistivity as well as the optical properties in the intraband region confirm the thesis on partial localization of the electronic states near the Fermi level.

Comparative study of the solid-state reaction (SSR) in a series of Ti/Ni multilayered films (MLF) with a bilayer period of 0.65-22.2 nm and a constant Ti to Ni sublayer thickness ratio has been performed by using the experimental and computer-simulated magneto-optical (MO) and optical spectroscopies as well as X-ray diffraction (XRD). It was shown that alloyed-like regions in an amorphous structure is spontaneously formed near the interfaces between pure elements during the film deposition. The thickness of this region was estimated as 2-3.8 nm on the basis of the MO and optical studies. The SSR in the Ti/Ni MLF caused by an annealing at 580 K for 60 min increases the thickness of these interfacial amorphous regions. It was shown that SSR takes place mainly in the Ti/Ni MLF with relatively “thick” sublayers. The existence of a threshold nominal Ni-sublayer thickness for observing the equatorial Kerr effect of about 3.0 and 4.5 nm for the as-deposited and annealed Ti/Ni MLF, respectively, is explained by formation of the nonmagnetic alloyed regions between pure components during the film deposition as a result of the SSR. For the case of Ti/Ni MLF, the MO and optical approaches turn out to be more sensitive in determining the thickness of the reacted zone, while XRD is more useful for the structural analysis. It was also shown that the very thin nonreacted Ni sublayers have different MO properties (and hence electronic structure) from the bulk.

In accordance with the condition of the maximum correspondence between lattice constants of monocrystalline ferrite-garnet film and gallium-gadolinium garnet substrate, for Y3-yLayFe5-xGaxO12 with saturation magnetizations 1000 and 1200 G, the compositions of fusion mixture for preparation of solutes-melts are calculated, and epitaxial films are grown up and investigated. As shown, the chemical composition of the ferrite-garnet film, its structural and magnetic parameters can be governed by the modification of the fusion-mixture molar coefficients, by the stage of a solute-melt supercooling, and by the condition of the substrate rotation.

The results of investigation of structure and magnetic properties of Co-rich microwires are presented. Initial Co69,8Fe4Ni1,5Si11,2Bi12Mo1,5 microwires covered with glass insulation are obtained by the Taylor-Ulitovsky technique. As shown, the crystallization of microwires occurs through the formation of the intermediate phase. The optimal soft-magnetic properties are obtained in initial amorphous state.