Polarization switching in metal-dielectric-metal structures with polycrystalline and heteroepitaxial (Ba,Sr) TiO3 films produced by cathode sputtering

The characteristics of polarization switching are studied in metal-dielectric-metal structures as the basis of (Ba, Sr)TiO₃ films having a different degree of crystal lattice perfection. The relationships discovered support the conclusions of a phenomenological model of the spreading of the ferroelectric phase transition, according to which microvolumes of the film material are distributed by the magnitude of deformation (the sum of spontaneous deformation and induced defects) and, consequently, by the magnitude of the spontaneous polarization, Curie temperature, coercive field, etc., while the half-width of this distribution is a measure of the average microdefect. The experimentally obtained results show that the items studied have promising applications in active and permanent computer memory devices.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 28–31, April, 1986.     

Alkaline hydrolysis of ethylp-nitrophenyl chloromethylphosphonate in the reverse micellar AOT—decane—water system

The influence of cluster formation of micelles on the rate of alkaline hydrolysis of ethylp-nitrophenyl chloromethylphosphonate in the reverse micellar sodium bis(2-ethylhexyl) sulfosuccinate (AOT)—decane—water system was found. The applicability of the pseudo-phase model of micellar catalysis below and above the percolation threshold was shown. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2266–2270, December, 1999.     

Use of various growth catalysts for laser sputtering of ZnO micro- and nanorods

Pulsed laser deposition and various catalysts are used to fabricate ZnO micro- and nanorods at temperatures close to the optimum temperature for each catalyst. A comparative analysis of the optical and structural properties of the rods shows that, as the temperature of growth on Al₂O₃(11–20) substrates decreases, the internal stresses in the rods decrease, which improves their structure and optical properties. This effect is not observed for GaN/Si substrates because of the high stresses induced by the difference in the lattice parameters. An increase in the synthesis temperature leads to an increase in the lattice strains and the concentration of point defects, the relaxation of selection rules, and the appearance of numerous phonon A ₁(LO) overtones. The lattice strains calculated from unit cell parameter a and the shift in the phonon A ₁(LO) frequency agree qualitatively. The study of the photoluminescence of the rods shows that a decrease in the synthesis temperature decreases the imperfection of the ZnO rods and improves their optical properties for UV applications.