Generation of second optical harmonic and magnetooptical Kerr effect in ferromagnet-semiconductor heterostructures CaF2/MnAs/Si(111)

The second optical harmonic generation and magnetooptical Kerr effect are investigated for the light (λ=800 nm) reflected by ferromagnet-semiconductor heterostructures CaF₂/MnAs/Si(111). The observed change in the second-harmonic intensity is odd in magnetization. A phenomenological analysis of possible contributions to the second harmonic is carried out, and the sources of optically nonlinear signals are determined from the experimental azimuthal dependences of the light intensity at double frequency. The difference in the field dependences of the second harmonic and the magnetooptical Kerr effect is observed.     

Experimental investigation of CO vibrational deactivation in a supersonic cooling gas flow

Abstract. The vibrational relaxation time of CO molecules at collisions with H atoms was measured in shock tube experiments by means of the CARS-spectroscopy method. The measurements of the CO vibrational temperature at gas temperatures of 1800–3000 K were performed in a supersonic cooling gas flow. The gas was heated behind the incident and reflected shock wave and then flowed out of a wedge-shaped nozzle. H atoms were generated in the reflected shock wave because of dissociation of H and HO admixtures. The extremely high efficiency of H atoms in CO vibrational deactivation was confirmed. Received 1 February 2000 / Accepted 20 February 2000     

Thermal decomposition of ammonium dinitramide and mechanism of anomalous decay of dinitramide salts

Thermal decomposition of ammonium dinitramide proceedsvia homolytic rupture of the N−NO₂ bond and partially by the proton transfer reaction. The monomolecular decay of the anion to N₂O and NO₃ ⁻ in the solid state at 60 °C occurs with higher rates than those in the melt. This is related to a change in the reactivity of the anion due to the violation of its symmetry on going to the solid state. The absence of hydrogen bonds between the anion and cations or water molecules is an additional condition for the fast decay. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 50–54, January, 1999.     

Electron emission during pulsed polarization switching of ferroelectric ceramics

It is shown that in the pulsed polarization switching of polycrystalline ferroelectrics in high fields the external field is damped by the electronic subsystem associated with the crystallite boundaries. Therefore, the reorganization of a ferroelectric system with a high density of surface states at the crystallite boundaries is not irreversible, and the system returns to its former state after the polarization-switching voltage is removed. Because of this, electron emission from the surface of a ferroelectric ceramic can be brought about by unipolar pulses. Zh. Tekh. Fiz. 69, 49–52 (July 1999)     

Negative Electrodes for Lithium-Ion Batteries Obtained by Photoanodization of Solar-Grade Silicon

Technical Physics - Negative electrodes for lithium-ion batteries prepared by electrochemical etching of single-crystalline silicon crystals demonstrate a high specific capacity per gram of the...     

An Investigation of the Conductive and Ferroelectric Properties of BZT Films

Technical Physics - Local polarization processes in BaTi1 – xZrxO3 thin films are studied using contact conductive scanning probe microscopy and piezoelectric response microscopy. The...     

Theoretical and Experimental Study of a Compact Planar Slow-Wave Structure on a Dielectric Substrate for the W-Band Traveling-Wave Tube

Technical Physics - A miniature planar meander-type slow-wave structure (SWS) for a W-band traveling-wave tube is studied. Computer simulation of the SWS electrodynamic parameters is performed. A...     

O- and S-containing 1-azadiene derivatives of 3-aminopropylsilatrane

Russian Chemical Bulletin - Silatranes bearing the aryl(hetaryl)-substituted 1-azadienyl moiety ((Het)ArCH=C(YR) C(H)=N- (Y = O, S)) were synthesized by the reaction of 1-(3-aminopropyl)silatrane...     

Synthesis of azolyl-substituted adamantane derivatives and their coordination compounds

Russian Chemical Bulletin - Reactions of adamantylazoles with nucleophiles (water, carbon monoxide, acetonitrile) in sulfuric acid were studied. New bifunctional adamantane derivatives containing...