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61.
I. Yu. Yaroslavtsev B. L. Kuzin D. I. Bronin G. K. Vdovin N. M. Bogdanovich 《Russian Journal of Electrochemistry》2009,45(8):875-880
The electrochemical characteristics of composite cathodes made of (La, Sr) MnO3-(Zr, Sc)O2 (LSM-SSZ), modified with PrO2 − x
additive, and designed for application in solid oxide fuel cells at moderately high temperatures were studied. The relationship
between activity of catalytically modified composite LSM-SSZ cathodes and dispersity of electrocatalyst was revealed. The
boundaries of the temperature range with the maximum dispersity of electrocatalyst and electrochemical activity of cathodes
were found. The composite LSM-SSZ cathodes modified with PrO2 − x
were shown inert with respect to oxidation reactions of hydrocarbon fuel (methane) and highly active electrochemically with
respect to oxygen reaction in non-equilibrium gas mixture of CH4 and O2. In cells with (Ce, Sm)O2 (SDC) and (Zr, Y)O2 (YSZ) electrolytes, their overvoltage is below 80 mV at the current density about 0.5 A/cm2 and temperature of 600°C. These electrodes can be used as cathodes in single-chamber fuel cells. Long-term experiments were
carried out to study time stability of characteristics of the said composite cathodes. The studied electrodes show parabolic
or damped exponential time curves of polarization resistance if contacting with YSZ or SDC electrolyte, respectively. According
to the forecast based on the experimental regularities, the polarization resistance of LSM-SSZ cathodes in 10,000 h will not
exceed 0.4 or 0.13 Ohm cm2, respectively, if YSZ or SDC electrolyte is used. 相似文献
62.
Works, mostly experimental, concerning the most interesting features of application of the resonant tunneling spectroscopy to a new type of heterosystems, van der Waals heterostructures, have been briefly reviewed. These heterostructures appeared after the recent discovery of two-dimensional crystals, which are a new class of materials beginning with graphene. The role of the angular matching of crystal lattices of conducting graphene electrodes of van der Waals systems in carrier tunneling between them has been analyzed together with the closely related problems of satisfaction of conservation laws in tunneling transitions. Manifestations of multiparticle correlation interactions between carriers in van der Waals systems such as Wigner crystallization of electrons in a two-dimensional electron gas in a magnetic field and Bose condensation of excitons in parallel two-dimensional electron gases have been briefly discussed. 相似文献
63.
Yu. N. Khanin E. E. Vdovin I. A. Larkin O. Makarovsky Yu. A. Sklyueva A. Mishchenko Yi Bo Wang A. Kozikov R. V. Gorbachev K. S. Novoselov 《JETP Letters》2018,107(4):238-242
Resonance magnetic tunneling in heterostructures formed by graphene single sheets separated by a hexagonal boron nitride barrier and bounded by two gates has been investigated in a strong magnetic field, which has allowed observing transitions between spin- and valley-split Landau levels with various indices belonging to different graphene sheets. An unexpected increase with the temperature in the interlayer tunneling conductance owing to transitions between the Landau levels in strong magnetic fields cannot be explained by existing theories. 相似文献
64.
65.
Makarovsky O Vdovin EE Patané A Eaves L Makhonin MN Tartakovskii AI Hopkinson M 《Physical review letters》2012,108(11):117402
We use a femtowatt focused laser beam to locate and manipulate a single quantum tunneling channel associated with an individual InAs quantum dot within an ensemble of dots. The intensity of the directed laser beam tunes the tunneling current through the targeted dot with an effective optical gain of 10(7) and modifies the curvature of the dot's confining potential and the spatial extent of its ground state electron eigenfunction. These observations are explained by the effect of photocreated hole charges which become bound close to the targeted dot, thus acting as an optically induced gate electrode. 相似文献
66.
S. M. Beresnev O. F. Bobrenok B. L. Kuzin N. M. Bogdanovich A. A. Kurteeva D. A. Osinkin G. K. Vdovin D. I. Bronin 《Russian Journal of Electrochemistry》2012,48(10):969-975
Single fuel cells with bilayer supported cathodes are manufactured and tested. The cathodes consist of a high-porous La0.6Sr0.4MnO3 support with the thickness of approximately 1 mm and a functional composite layer with the thickness of 13?C15 ??m made of La0.75Sr0.2MnO3 and 8YSZ. Voltammetric and power characteristics of single fuel cells with a supported cathode, thin-film YSZ electrolyte, and platinum cathode are determined. The conclusion as to the significant contribution into the polarization overpotential losses on the cathode is made on the basis of the measurements of electric fuel cell characteristics. It decreases significantly as a result of the supported cathode modification by praseodymium oxide. At 850°C and voltage of 0.81 V, electric power density of a fuel cell was 1.65 W/cm2. 相似文献
67.
A. V. Vdovin V. N. Moiseenko V. S. Gorelik Ya. V. Burak 《Physics of the Solid State》2001,43(9):1648-1654
The polarized infrared reflection spectra of Li2B4O7 were studied in the spectral range 80–1600 cm?1 and compared with Raman spectra. From the spectrum dispersion analysis, the frequencies, damping, and dielectric oscillator strengths were determined for all vibrational modes observed. A calculation of the effective charges and an analysis of the chemical-bond types of the Li2B4O7 crystal structural units were carried out on the basis of the obtained data. 相似文献
68.
Polarized IR reflection spectra of Li2B4O7 crystals are studied in a spectral range of 80–1600 cm?1 and compared with their Raman spectra. Based on the results of the dispersion analysis of the spectra, the frequencies, damping constants, and oscillator strengths of all vibrations are determined. The inversion of frequencies of the longitudinal and transverse vibrations of the A 1 and E symmetry in a range of 900–1150 cm?1 is found. Based on the data thus obtained, the effective charges are calculated and the types of chemical bonds are analyzed for structural groups of the Li2B4O7 crystal. 相似文献
69.
É. A. Shteinman V. I. Vdovin A. N. Izotov Yu. N. Parkhomenko A. F. Borun 《Physics of the Solid State》2004,46(1):22-26
The photoluminescence spectra of silicon samples implanted by 56Fe+ ions [energy, 170 keV; dose, 1×1016, (2–4)×1017 cm?2] and annealed at temperatures of 800, 900, and 1000°C are measured. The structure of the samples at each stage of treatment is investigated using transmission electron microscopy (TEM). It is found that the phase formation and morphology of crystalline iron disilicide precipitates depend on the dose of iron ions and the annealing temperature. A comparison of the dependences of the intensity and spectral distribution of the photoluminescence on the measurement temperature, annealing temperature, and morphology of the FeSi2 phase revealed the dislocation nature of photoluminescence. 相似文献
70.