Pb5Ge3O11 ferroelectric films prepared by a modified sol—gel method

Single-crystal Pb₅Ge₃O₁₁ films 5–105 μm thick, adhering well to platinum substrates, were prepared by pyrolysis of metalorganic precursors in combination with in situ sol-gel processing. The best films consisted of densely packed crystallites ranging in size from 200 to 300 μm, with hexagonal habits. A welldefined ferroelectric transition was revealed at 170–180°C. The typical parameters of the films are ɛ₂₀ = 30–40, tan δ ≃0.02, ɛ_max ≃200, P_s = 3.2 μC/cm²,E _c = 16 kV/cm, and ρ = 10⁸-10⁹ Ω cm, in agreement (except for ɛ_max) with those of lead germanate crystals     

Magnetostatic surface waves in a ferrite/dielectric/metal structure magnetized by a linearly increasing transverse field

Propagation of magnetostatic surface waves (MSSWs) in a ferrite/dielectric/metal structure magnetized by a nonuniform field whose intensity linearly increases with the coordinate normal to the direction of the magnetic field is considered. Wave trajectories are calculated. The variation of the wave number, as well as the variations of the directions of the phase- and group-velocity vectors, is investigated. Possible transformations of some waves into other modes and conditions for MSSW radiation are formulated. The parameters of ferrite/dielectric/metal structures that can be used in backward-wave devices are determined.     

Deformation of a trunk pipeline under the effect of a seismic shift

An algorithm for engineering estimates of deformations in a pipeline as a result of a seismic shift is proposed. These estimates are compared with simulation of the process by the finite element method.     

Phase shift of surface magnetostatic waves propagating in nonuniformly magnetized ferrite films and ferrite-metal structures

It is shown that when surface magnetostatic waves propagate in a ferrite-metal structure magnetized by a linearly nonuniform field, the phase shift of these waves is many times greater than that accompanying propagation in a ferrite film and also in a ferrite-metal structure magnetized by a uniform field, and may reach extremely high values of tens of thousands of radians. This indicates that ferrite-metal structures magnetized by nonuniform fields are potentially useful for developing microwave shifters. Pis’ma Zh. Tekh. Fiz. 25, 79–84 (February 26, 1999)     

Critical states of uniaxial tension in an orthotropic metal

Plastic flow of a thin uniform sample under uniaxial tension is considered. The critical states at the start of neck formation and the neck length at the fracture point are determined. These states depend on the anisotropy coefficients and mechanical properties of the metal.     

Development of laser induced fluorescence diagnostic for measuring the parameters of plasma containing rare gas species

Laser induced fluorescence (LIF) technique development activity for measurement of plasma parameters in ITER divertor plasma is described. Helium density is the task of priority, but Doppler measurement of ion (atom) temperatures is also the aim of the program. The concept of ITER scenarios includes injection of "extrinsic" impurities (Ne, Ar, and Kr). It is possible to use the species as tracing elements for measurement of T(i), T(a). The program included modeling experiments on PNX-U (a multicusp trap with microwave argon plasma). Helium was added by puffing into discharge. Temperatures T(i)(Ar(1+)) and T(a)(He(0)) have been measured by scanning laser line across absorption line of species. Summarizing of fluorescence signals provided input data for estimation of Ar(1+) and He(0) densities via interpretative collisional-radiative models. Besides, the collisional-radiative model has been used for estimation of electron density using the ratio of fluorescence signals at 388.9 and 706.5 nm helium lines.     

Nonlinear dynamics of the magnetization in a ferrite plate with magnetoelastic properties under the conditions for orientational transition

The nonlinear dynamics of the orientational phase transition of the magnetization vector in a magnetoelastic medium is analyzed. It is demonstrated that the transition involves the precession of the magnetization vector accompanied by the elastic oscillations at the same frequency. The critical constants of magnetoelasticity, elasticity, and magnetization needed for the transition are determined. It is shown that, in real materials, the magnetoelastic interaction leads to an increase in the field of transition by several or several tens of oersteds. The conditions for and the possibility of an increase in this field by hundreds of oersteds are revealed.     

Excitation of hypersound by multiplication of the ferromagnetic resonance frequency in a magnetostriction transducer

With reference to the problem of increasing the frequency of hypersound excited by a magnetostriction transducer, the feasibility of multiplication of the frequency by multiplication of the eigenfrequency of the elastic resonator is considered. It is shown that efficient multiplication is possible only in odd harmonics of the excitation signal. For interpretation of the phenomenon observed, a model of nonlinear excitation due to multiplication of the values of the longitudinal and transverse magnetization components is proposed.     

Washing the hearth of blast furnaces with briquets made from scale

A comparative analysis made of the use of washing sinter and scale briquets to wash the hearth of blast furnaces showed that similar results are obtained in both cases. Scale briquets with a cement binder can be effectively used as a washing material for blast furnaces, which will make it possible to end the production of washing sinter, increase the productivity of sinter plants, and improve the quality of the sinter they produce. __________ Translated from Metallurg, No. 6, pp. 36–39, June, 2007.     

Effect of the nonaxial symmetry of an emitter-collector system on the temperature field of a thermionic fuel element

Institute of Nuclear Reactors, Russian Scientific Center of the I. V. Kurchatov Atomic Energy Institute. Space Power Inc., USA. Translated from Atomnaya Énergiya, Vol.75, No. 1, pp. 73–75, July, 1993.