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Rinkevich A.B.,RAS Institute of Metal Physics | Burkhanov A.M.,RAS Institute of Metal Physics | Samoilovich M.I.,Tekhnomash Central Research Technological Institute OAO | Belyanin A.F.,Tekhnomash Central Research Technological Institute OAO | And 2 more authors.
Russian Journal of General Chemistry | Year: 2013

The microwave properties of 3D nanocomposites based on opal matrices containing one or two transition metal particles have been investigated. Phase analysis of the nanocomposites has been carried out. Magnetic field dependences of transmission and reflection coefficients were obtained. Magnetic resonance and antiresonance spectra have been reconstructed. Frequency dependences of resonance and antiresonance amplitude have been obtained. It has been found that the magnetic resonance amplitude of a nanocomposite containing particles of two metals is essentially higher than that of a nanocomposite with particles of one metal. © 2013 Pleiades Publishing, Ltd.


Rinkevich A.B.,RAS Institute of Metal Physics | Perov D.V.,RAS Institute of Metal Physics | Samoylovich M.I.,Central Research Technological Institute TECHNOMASH | Klescheva S.M.,Central Research Technological Institute TECHNOMASH | Kuznetsov E.A.,Nizhny Tagil State Social Pedagogical Academy
Proceedings - 2013 International Kharkov Symposium on Physics and Engineering of Microwaves, Millimeter and Submillimeter Waves, MSMW 2013 | Year: 2013

In recent years, the infrared and microwave properties of opal matrices have been intensively studied [1]. It is thought that the opal matrices containing nanoparticles of magnetic materials in the intersphere voids may form a most promising class of materials used in centimeter- and millimeter-wave devices [2, 3]. Nickel-zinc, cobalt-zinc, and other ferrites seem to be proper materials for the filling owing to a lucky combination of such properties as high resistivity, low dielectric loss, high Curie temperature, and chemical stability. Application of microwave methods seems to be effective since these methods enables to estimate the dynamical and relaxation parameters of materials. Microwave properties of opal matrices containing the nanoparticles of different ferrite-spinels in the inter-sphere voids are discussed in this work. Microwave properties are measured at frequencies of millimeter waveband. Variations of a microwave signal passed through the magnetic nanocomposite occur mainly due to variations of the surface impedance under magnetic resonance condition and due to absorption of the wave. At higher frequencies the antiresonance is possible in fields lower than the resonance field. The antiresonance manifests itself as a maximum of transmission and/or reflection coefficients. © 2013 IEEE.


Rinkevich A.B.,RAS Institute of Metal Physics | Perov D.V.,RAS Institute of Metal Physics | Samoylovich M.I.,Central Research Technological Institute TECHNOMASH | Klescheva S.M.,Central Research Technological Institute TECHNOMASH | Kuznetsov E.A.,Nizhny Tagil State Social Pedagogical Academy
Proceedings - 2013 International Kharkov Symposium on Physics and Engineering of Microwaves, Millimeter and Submillimeter Waves, MSMW 2013 | Year: 2013

Photonic crystals become fashionable object of investigation on microwaves and the interest is caused both basic scientific aspects and possible applications [1]. Reflection, transmission and absorption properties are under study [2]. Microwave methods give a unique opportunity to estimate the dynamic and relaxation parameters of spins in a nanostructure. Magnetic properties of magnetophotonic crystals based on opal matrices have been studied as well as their electromagnetic properties in millimeter waveband. Cobalt nanoparticles could be suitable magnetic component of a magnetophotonic crystal. The particles of cobalt oxide are embedded into the inter-sphere voids of the matrix. After annealing in hydrogen the cobalt oxide particles transform to metallic cobalt. It has been shown that if antiferromagnetic cobalt oxide remains besides ferromagnetic cobalt, the low-temperature magnetic hysteresis loop is shifted along the field axis. Magnetic field influences essentially on the microwave transmission and reflection coefficients only after annealing in hydrogen that is if the ferromagnetic phase presents in the sample. The spectra of magnetic resonance and antiresonance are studied. © 2013 IEEE.


Ivshina I.B.,Russian Academy of Sciences | Kostina L.V.,Russian Academy of Sciences | Kamenskikh T.N.,Russian Academy of Sciences | Zhuikova V.A.,Nizhny Tagil State Social Pedagogical Academy | And 2 more authors.
Russian Journal of Ecology | Year: 2014

The soil microbiota, a key component of natural ecosystems, is considered as a factor determining the stability of meadow communities. The diversity and abundance of the main ecologically significant groups of microorganisms in meadow soils have been studied along a gradient of long-term soil pollution with heavy metals in the Middle Urals. The results provide evidence for stability of the microbial assemblage formed in these soils. It has been found that the functional activity of certain physiological groups of microorganisms (nitrogen-fixing, denitrifying, and cellulolytic bacteria) and the respiratory activity of microbial communities are stimulated under conditions of heavy-metal soil pollution. Probable effects of the observed changes on mineralization of plant remains in meadow communities are discussed. © 2014 Pleiades Publishing, Ltd.


Zhuikova T.V.,Russian Academy of Sciences | Meling E.V.,Nizhny Tagil State Social Pedagogical Academy | Kaigorodova S.Y.,Russian Academy of Sciences | Bezel' V.S.,Russian Academy of Sciences | Gordeeva V.A.,Nizhny Tagil State Social Pedagogical Academy
Russian Journal of Ecology | Year: 2015

Anthropogenic transformation of soils and specific features of herbaceous plant communities have been studied in areas polluted with heavy metals. With regard to landscape and edaphic conditions, all test areas have been divided into two groups: agrozems and technozems. Phytocenoses in test areas of the background and buffer zones belong to the glycophytic variant of meadow vegetation type and to the premeadow stage of progressive succession, respectively. Chemical pollution leads to a decrease in coefficients of similarity between communities and an increase in taxonomic diversity due to reduction in species saturation of genera and families, with a rise in the proportion of monotypic taxa. The influence of chemical pollution on the species saturation of plant communities is stronger than that of community type and coverage of species. © 2015, Pleiades Publishing, Ltd.

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