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1.
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.
Russian Journal of Applied Chemistry - The optimization of the molecular structure of substituted 3,5-toluylene diamines was carried out by the ab initio method, which made it possible to calculate...  相似文献   
3.
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   
4.
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   
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6.
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   
7.
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   
8.
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   
9.
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   
10.
Physics of the Solid State - The multilayer amorphous nanostructure [(CoFeB)60C40/SiO2]200 of alternating composite and dielectric layers was obtained by ion-beam sputtering on a rotating...  相似文献   
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