[en] The width of stripe domains in the absence of a magnetic field has been determined for TmFeOsub(3), DyFeOsub(3), ErFeOsub(3), and YbFeOsub(3) crystals between 80 and 400degK, and the domain wall energy γ has been calculated. At room temperature the values of γ for these materials are respectively 1.6,2.2,1.8, and 1.55 erg/cmsup(2). The maximum and minimum diameters of cylindrical domains were determined in the same temperature range along with the corresponding magnetizing field. It has been showed that in TmFeOsub(3) and DyFeOsub(3) these parameters change with temperature by several fold, while in ErFeOsub(3) and YbFeOsub(3) these changes do not exceed 30 to 40%

[en] Using scanning microscopy shape and orientation of pores in ZnNi(Co)Fe₂O₄ were studied

[en] Structural analogy of two classes of rare-earth compounds, fluorides LnF₃ (Ln=Sm-Lu) and oxides LnFeO₃ (Ln=Pr-Lu), has been established. Reduction of the coordination number of the Ln³⁺ cation in these compounds occurs due to displacement of O or F atoms, leading to an increase in certain cation-anion distances. Anisotropy in the change of individual interatomic distances determines non-monotonicity of the curve of parameters of the crystal lattice in the series LnF₃ and LnFeO₃

[en] This paper describes the research and development activities of the Philippine Nuclear Research Institute (PNRI) on the synthesis and characterization of soft and hard ferrites and some beta alumina type superionic conductor materials. XRD, XRF and Moessbauer effect spectrometry are used to determine the structure phases, compositions and some magnetic properties of the materials. Effects of composition and preparation methods on the bulk electronic and magnetic properties are also discussed. (Auth.). 6 figs.; 3 tabs

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[en] The Lawrence Livermore Laboratory undertook an investigation of the properties of ferrite materials to be used in a 5-MeV, 50-ns linear induction accelerator. The investigation, on a part-time basis, lasted about one year and had the cooperation and helpful suggestions of several manufacturers: TDK of Japan, Phillips of Holland, and Stackpole of the U.S.A. Ferrites have been widely used as tuning cavities for proton synchrotron accelerators at radio frequencies. In such an application, the μQf factor is used in describing the figure of merit for ferrites where a high duty factor requires low loss ferrites. In a linear induction accelerator with an average reprate of 5-Hz, the ferrite losses are negligible and the concept of complex permeability in describing the losses will not be introduced, but a large signal ΔB/ΔH will be used to describe their properties. The properties of interest in designing the accelerating cavity were (1) flux swing ΔB = B/sub r/ + B/sub m/ greater than 0.5T; (2) a residual flux density B/sub r/ greater than or = to 0.15T with a reset no greater than 2 Oer; (3) a relatively high incremental μ greater than 400 to keep the excitation current small in relation to the load current; and (4) a high resistivity for the 250-kV voltage hold-off

[en] Catalytic activity of some ferrites rare earth elements (r.e.e.) in the reaction CO+O₂+CO₂ was studied. Ferrites of Ce, Eu, Pr were considered and their catalytic activity was compared with praseodymium cobaltite. Ferrites of r.e.e. have perovskite or garnet structure. It is noticed that praseodymium cobaltite PrCOO₃ has higher catalytic activity at low temperature. The closest to it by catalytic activity at 300 deg C is PrFeO₃. At the same time activation energy of reaction with PrFeO₃ is higher than for PrCOO₃. Ferrite of cerium and europium have lower catalytic activity than cobaltite and praseodimium ferrite

[en] Individual magnetic steel rotors were levitated by combining the attractive force between permanent magnets and the steel with the repulsive force between high-temperature superconductors and the steel. The free spindown of several rotors was observed, and the effective coefficient of friction for the bearing was calculated as a function of geometry. Low-speed coefficients of <10^-8 were observed, and the velocity dependence of MnZn ferrite rotors suggest that coefficients of <10^-6 are attainable at bearing rim velocities of 100 m/s