"Technical Physics Letters"

Moseev, N. V.

doi: 10.1134/1.1262565pmid: N/A

Abstract A molecular statics method is used to calculate the energy barriers for the migration of oxygen ions. Vacancy and interstitial diffusion mechanisms are considered. The lowest migration barrier is obtained for the vacancy mechanism.

Bibilashvili, A. P.;Gerasimov, A. B.;Kazarov, R. É.;Samadashvili, Z. D.

doi: 10.1134/1.1262566pmid: N/A

Abstract The use of catalytic plasma anodization to obtain oxides on the surface of SiC is an original method, hitherto unused. This method can significantly reduce the process temperature, increase the oxide growth rate, and improve the properties of the structures, giving a low density of surface states and a small fixed charge in the oxide.

Zhuravlev, K. S.;Toropov, A. I.;Shamirzaev, T. S.;Bazarov, A. K.;Rakov, Yu. N.;Myakishev, Yu. B.

doi: 10.1134/1.1262567pmid: N/A

Abstract The fabrication of high-purity layers of AlxGa1−x As solid solutions in the range 0⩽x⩽0.38 by molecular beam epitaxy is reported. The low-temperature photoluminescence spectra of these layers reveal predominantly the free exciton recombination line (X). The narrow width of the X line, the high intensity ratio of this line to that of the band-acceptor transition line, and the linear dependence of the X line intensity on the excitation power density in the range between 1×10−4 and 100V·cm−2 indicate a low concentration of background impurities in these layers. Using this material in pseudomorphic AlGaAs/InGaAs/GaAs heterostructures for high-power microwave transistors produced devices with a specific saturated output power of 0.9 W/mm at 18 GHz.

Pikhtin, N. A.;Il’in, Yu. V.;Leshko, A. Yu.;Lyutetskii, A. V.;Stankevich, A. L.;Tarasov, I. S.;Fetisova, N. V.

doi: 10.1134/1.1262568pmid: N/A

Abstract An InGaAsP/InP separate-confinement double heterostructure having a broad gain profile was used to fabricate superluminescent diodes having high optical power (40 mW), a broad radiation spectrum (65 nm at half-width), and low percent modulation (<1%). Using a cw pump current of 150 mA, 1mW of superluminescence radiation was obtained at the exit from a single-mode optical fiber.

Davydov, S. Yu.;Solomonov, A. V.

doi: 10.1134/1.1262569pmid: N/A

Abstract The Keating model is used to calculate the elastic constants of GaN and AlN for sphalerite and wurtzite structures. The following values of the elastic constants (in gigapascals) were obtained for cubic gallium and aluminum nitride: C 11=325 and 322, C 12=142 and 156, C 44=147 and 138.

Kharlamov, V. F.;Anufriev, K. M.

doi: 10.1134/1.1262570pmid: N/A

Abstract Relaxation measurements are used to establish that for a concentration of gas-phase oxygen atoms n=1014 cm−3 heterogeneous recombination of oxygen atoms at the surface of copper and zinc sulfide takes place by a mechanism involving recombination of preadsorbed (precursor state) atoms. A hypothesis is put forward for the existence of a universal mechanism for the catalytic acceleration of heterogeneous chemical reactions.

Kuteev, B. V.;Kostryukov, A. Yu.

doi: 10.1134/1.1262571pmid: N/A

Abstract An analysis is made of an effect involving increased evaporation and toroidal acceleration of pellets during their repeated injection in a tokamak, caused by an avalanche-like growth in the population of runaway electrons additionally stimulated by the pellet injection.

Belonozhko, D. F.;Grigor’ev, A. I.

doi: 10.1134/1.1262572pmid: N/A

Abstract The nonlinear problem of the capillary oscillations of a charged droplet is solved to estimate the characteristic time for the evolution of instability of a droplet carrying critical charge. It is observed that breakup is delayed because of the hydrodynamic inertia of the droplet.

Pshenichnyuk, S. A.;Yumaguzin, Yu. M.;Bakhtizin, R. Z.

doi: 10.1134/1.1262573pmid: N/A

Abstract Results are presented of measurements of the total energy distributions of electrons emitted under the action of a strong external field from the surface of a thin diamond-like film, fabricated by ion-beam deposition on a tungsten tip. The data confirm that carriers are injected into the conduction band of the film and then emitted into vacuum.

Duvanov, S. M.;Baturin, V. A.

doi: 10.1134/1.1262574pmid: N/A

Abstract Results are presented of an investigation of distribution profiles of implanted Ti atoms at high implantation doses (fluence around 1017 cm−2) over the depth of boron nitride (BN) nanocrystalline ceramic. It is observed that the concentration maxima of implanted impurities are shifted into the substrate under post-implantation annealing in vacuum at 950 °C. This behavior of the implanted impurities in BN is directly the opposite of that observed in earlier studies of polycrystalline aluminum oxide ceramic exposed to similar ion thermal treatment. The effective diffusion coefficient of titanium atoms in BN under thermal annealing is estimated. The Ti/O concentration ratio in the layer modified as a result of implantation and subsequent annealing at 950 °C is close to stoichiometric TiO2. A simultaneous increase in the concentration of carbon and nitrogen atoms in the surface layers of BN samples was observed as a result of annealing at 830 and 950 °C.