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1.
P. P. Kirpichok N. B. Voronina A. F. Sitnikov V. Ya. Garmash 《Russian Physics Journal》1989,32(1):26-30
The effect of rare-earth oxides on the properties of anisotropic barium ferrites has been studied by x-ray structural and Mössbauer methods. Additions of SrCO3, as well as SrCO3 and La2O3, SrCO3 and Pr6O11, SrCO3 and Nd2O3, SrCO3 and Sm2O3 in amounts of 7.5 mole % Sr and 10 mole % rare-earth element to grade-A barium powder results in the substitution of barium ions by Sr and rare-earth ions; consequently, the energy of magnetic anisotropy changes and the technically important parameters Br and (BH)max increase.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 34–39, January, 1989. 相似文献
2.
The generation of matter in an extreme state with precisely measurable parameters is of great interest for contemporary physics. One way of obtaining such a state is to irradiate the end of a hollow cylindrical shell at the center of which a test material is kept at a temperature of several Kelvin by an annular beam of high-energy heavy ions. Under the action of the beam, the shell starts explosively expanding both outwards and inwards, compressing the material to an extremely high pressure without subjecting it to direct heating. A method of producing a hollow cylindrical beam of high-energy heavy ions using a resonance rf deflector is described. The deflection of the beam in two transverse directions by means of an rf electric field allows it to rotate about the longitudinal axis and irradiate an annular domain on the end face of the target. 相似文献
3.
J. V. Kasiuk J. A. Fedotova M. Marszalek A. Karczmarska M. Mitura-Nowak Yu. E. Kalinin A. V. Sitnikov 《Physics of the Solid State》2012,54(1):178-184
The elemental and phase compositions and the magnetic state of metal particles in FeCoZr-Pb(ZrTi)O3 granular nanocomposites (GNCs) synthesized by ion-beam sputtering of composite targets in oxygen-containing media at different
oxygen partial pressures have been studied. The phase transformations in GNCs have been monitored by the Raman and M?ssbauer
spectroscopy techniques. Correlation between the oxygen pressure during GNC synthesis and the valence state of iron ions in
metal granules has been established. It has been confirmed that (i) the degree of metal oxidation increases with increasing
oxygen pressure and (ii) the degree of crystallinity of oxides increases as a result of annealing. It has been established
that the percolation threshold in GNCs can also be varied by changing the oxygen pressure during GNC synthesis. 相似文献
4.
5.
V. A. Belousov A. B. Granovsky Yu. E. Kalinin A. V. Sitnikov 《Physics of the Solid State》2007,49(10):1848-1855
The concentration and temperature dependences of the thermopower of composites containing Co nanoparticles embedded in the Al2O n dielectric matrix are investigated. Below the percolation threshold, i.e., in the tunneling conduction region, the absolute values of the thermopower of the composites under investigation are less than those above the percolation threshold. It is revealed that, in the tunneling conduction region, the slope of the temperature dependences of the thermopower changes at a temperature of ~205 K. This can indicate that the thermopower is sensitive to a change in the mechanism of conduction from the Mott law ln(σ) ∝ (1/T)1/4 to a power relation that corresponds to the model of inelastic resonant tunneling through a chain of localized states in the dielectric matrix. The introduction of oxygen in the course of sputtering brings about a decrease in the absolute values of the thermopower; however, the character of variation in the concentration and temperature dependences of the thermopower remains unchanged. 相似文献
6.
Transport Properties of Magnetic Nanogranular Composites with Dispersed Ions in an Insulating Matrix
Rylkov V. V. Emelyanov A. V. Nikolaev S. N. Nikiruy K. E. Sitnikov A. V. Fadeev E. A. Demin V. A. Granovsky A. B. 《Journal of Experimental and Theoretical Physics》2020,131(1):160-176
Journal of Experimental and Theoretical Physics - This review is devoted to an analysis of the electrical resistance, the magnetoresistance, and the anomalous Hall effect in magnetic... 相似文献
7.
Dr. Vladimir V. Shilovskikh Alexandra A. Timralieva Pavel V. Nesterov Dr. Alexander S. Novikov Dr. Petr A. Sitnikov Prof. Elizaveta A. Konstantinova Prof. Alexander I. Kokorin Prof. Ekaterina V. Skorb 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(70):16603-16610
In the last two decades, a large number of self-assembled materials were synthesized and they have already found their way into large-scale industry and science. Hydrogen-bond-based supramolecular adducts are found to have unique properties and to be perfect host structures for trapping target molecules or ions. Such chemical systems are believed to resemble living matter and can substitute a living cell in a number of cases. Herein, a report on an organic material based on supramolecular assembly of barbituric acid and melamine is presented. Surprisingly, the structure is found to host and stabilize radicals under mild conditions allowing its use for biological applications. The number of free radicals is found to be easily tuned by changing the pH of the environment and it increases when exposed to light up to a saturation level. We describe a preparation method as well as stability properties of melamine–barbiturate self-assembly, potentiometric titration, and hydrogen ions adsorption data and EPR spectra concerning the composite. 相似文献
8.
J. Fedotova J. Kalinin A. Fedotov A. Sitnikov I. Svito A. Zaleski A. Jablonska 《Hyperfine Interactions》2005,165(1-4):127-134
The effect of oxygen-containing ambient arising at sputtering of granular nanocomposites (Fe0.45Co0.45Zr0.10)
x
(Al2O3)1−x
(30 at.%≤x≤65 at.%) on their magnetic state and phase composition has been investigated. It was shown that the presence of oxygen resulted
in the formation of oxide shells preventing the ferromagnetic interaction between Co0.45Fe0.45Zr0.10 nanoparticles and also the formation of metallic percolative net beyond the percolation threshold (as opposed to the films
prepared in pure argon atmosphere). 相似文献
9.
E. Yu. Loktionov A. V. Ovchinnikov Yu. Yu. Protasov D. S. Sitnikov 《Journal of Applied Spectroscopy》2010,77(4):561-568
We present the results of an experimental study of the ablation energy thresholds and ablated mass for a number of refractory
metals (Ti, Zr, Nb, Mo) by femtosecond (τ
0.5 = 45–70 fs) exposed to laser pulses in the ultraviolet — near infrared range (λ = 266, 400, 800 nm) under atmospheric conditions and under vacuum (p ~ 10–2 Pa). We have analyzed the ablation efficiency (mass yield per unit energy of the acting coherent radiation) and ablation
energy thresholds vs. the laser pulse duration and photon energy. 相似文献
10.
N. A. Dontsova Yu. E. Kalinin M. A. Kashirin A. B. Sitnikov 《Bulletin of the Russian Academy of Sciences: Physics》2013,77(10):1296-1299
The electrical properties and magnetoresistance of (Co41Fe39B20) x (CaF2)100 ? x composite are investigated. The principal mechanisms of electric charge transfer at low temperatures are determined. The effective density of localized states at the Fermi level and the average number of localized states between adjacent granules at various concentrations of the metal phase are estimated. 相似文献