"Technical Physics Letters"

Krasin’kova, M. V.

doi: 10.1134/1.1262533pmid: N/A

Abstract It is shown that a giant negative magnetoresistance effect in doped manganites can be explained using a model developed earlier to explain high-temperature superconductivity, based on allowance for the covalence of the transition metal-oxygen bond. This effect is caused by delocalization of π-electrons along asymmetric π-orbitals belonging to chains of covalently coupled Mn and O ions. Unlike high-temperature superconductors, in manganites this delocalization is induced by a magnetic field which ferromagnetically orients unpaired π-electrons and thereby lifts the restriction against their collective motion along the π-orbital when the manganese ions are ferromagnetically ordered.

Venus, G. B.;Gadzhiev, I. M.;Gubenko, A. E.;Il’inskaya, N. D.;Portnoi, E. L.

doi: 10.1134/1.1262534pmid: N/A

Abstract A method of implanting high-energy heavy ions across the emitter layer of a semiconductor laser has been developed to create distributed regions of ultrafast saturable absorber integrated into the cavity of a quantum-well laser. This method was used to fabricate picosecond laser diodes having high average powers and to demonstrate colliding-pulse mode-locking of a diode laser with a multisection saturable absorber.

Kortkhondzhiya, V. P.;Mdivnishvili, M. O.

doi: 10.1134/1.1262535pmid: N/A

Abstract It is shown that if the explosion of a wire in a liquid is accompanied by a chemical reaction between the wire material and the liquid in which the wire explodes, the chemical reaction products are the main mechanism responsible for creating pressure pulses.

Plotnikov, V. A.

doi: 10.1134/1.1262536pmid: N/A

Abstract Athermal (above-barrier, critical-velocity) motion of the martensite boundary is accompanied by the production of spontaneous transition radiation and (or) spontaneous acoustic bremsstrahlung. The acoustic transition radiation is strongly related to the velocity of the interphase boundary and the correlated (coherent) nature of the formation of a set of martensite crystals. Conversely, the bremsstrahlung is produced when the correlation is destroyed.

Anneli, J. N.;Bolotashvili, M. M.

doi: 10.1134/1.1262537pmid: N/A

Abstract A method of fabricating a high-temperature superconducting ceramic is proposed and described. This method can produce a material having a higher impact strength and lower degradation in air than that obtained by other methods.

Kozlov, A. N.;Lyakhov, G. A.;Pavlov, Yu. V.;Reznikov, A. E.;Umarkhodzhaev, R. M.;Shlifer, É. D.

doi: 10.1134/1.1262538pmid: N/A

Abstract An experimental investigation was made of the transient emission of a discharge excited by microwave radiation in mixtures of sulfur and rare gases. Several typical spectral types of emission were identified which alternate over time.

Katerinchuk, V. N.;Kovalyuk, Z. D.;Zaslonkin, A. V.

doi: 10.1134/1.1262539pmid: N/A

Abstract Oxide-p-InSe heterojunctions were formed by thermal oxidation of a p-InSe crystal substrate in various temperature-time regimes. Measurements of the current-voltage characteristics confirmed that these were of good optical quality. The optimum technological conditions for fabricating these junctions were determined.

Kagadei, V. A.;Lilenko, Yu. V.;Shirokova, L. S.;Proskurovskii, D. I.

doi: 10.1134/1.1262540pmid: N/A

Abstract It has been established that hydrogenation of ion-doped gallium arsenide structures can be used to suppress parasitic backgating. Curves describing the degree of suppression of the backgating as a function of the hydrogenation regimes are given. The observed dependence is evidently caused by the formation and decay of hydrogen complexes with deep centers.

Akhmetov, A. A.;Ivanov, S. S.;Shchegolev, I. O.

doi: 10.1134/1.1262541pmid: N/A

Abstract A matrix method is used to investigate the current damping process in a flat superconducting cable. A discrete spectrum of natural frequencies is obtained, each determining the rate of exponential damping of the corresponding induced current. Although the number of natural frequencies increases as the size of the cable increases, their spectrum remains finite because the maximum and minimum frequencies tend to finite limits. An analysis is made of the induced currents for the limiting frequencies. It is shown that in the range of minimum natural frequencies the induced currents are long-lived long current loops. At high frequencies the distribution of the induced currents in cable layers is sinusoidal.

Bal’makov, M. D.;Blinov, L. N.;Murin, I. V.;Pocheptsova, N. S.

doi: 10.1134/1.1262542pmid: N/A

Abstract It is shown that the maximum information capacity of a condensed system is determined by the number of its equilibrium configurations. An analytic expression is obtained for the upper limit of the possible values of the information capacity. The problem of preserving stored information is discussed.