• Articles | Статьи

Vibrational Spectra of Platinum Superoxo Complexes

Raman spectra of solutions of hexahydroxoplatinate(IV) and а syperoxo platinum(IV) соmрlех in 3 М КОН

Vibrational spectra of platinum superoxo complexes. Pankratov D.A., Kiselev Yu.M., Sokolov V.B. //Russian Journal of Inorganic Chemistry. 2000. V. 45. № 9. P. 1388-1393Search the full text below. Ищи полный текст ниже.

Aqueous alkaline (KOH, KOD) solutions of hexahydroxoplatinate and "blue" superoxohydroxo-platinate complexes were studied by Raman spectroscopy. The spectra of superoxo complexes shows the bands at 1020 and 1060 cm-1 that arise from the O2- moiety. Solid samples of platinum hydroxide and the precipitates isolated from "blue" solutions were studied by IR and Raman spectroscopy. The spectra of hexahydroxoplatinate(IV) were assigned assuming the C3i symmetry of the Pt(OH)62- group. The Raman spectra of the decomposition products of the solid superoxo complex (νO-O = 1080 cm-1 for O2-) show the bands that arise from a platinum peroxo complex (νO-O = 829 cm-1 for O22-).

Подробнее...

Печать E-mail

Ab Initio Calculations Of Hydroxoplatinum Compounds: II. Binuclear Platinum(IV) Superoxo Complexes

Equilibrium structure of the binuclear monobridged platinum superoxo complexes [(OH)5Pt(μ-O2)Pt(OH)5]3–Ab Initio Calculations Of Hydroxoplatinum Compounds: II. Binuclear Platinum(IV) Superoxo Complexes. Pankratov D.A., Dement'ev A.I., Kiselev Yu.M. //Russian Journal of Inorganic Chemistry. 2008. V.53. №2. P.247-253.Search the full text below. Ищи полный текст ниже.

The structural and spectral data have been obtained by ab initio methods for the [(OH)4Pt(μ-O2)(μ-OH)Pt(OH)4]2-, [(OH)4Pt(μ-O2)(μ-OH)Pt(OH)4(OH)]3-, [(OH)5Pt(μ-O2)Pt(OH)5]3-, and [(H2O)(OH)4Pt(μ-O2)Pt(OH)4•(H2O)]- clusters, corresponding to binuclear platinum (IV) superoxo complexes with one and two bridges. The data obtained are in good agreement with experimental data and make it possible to judge the structure of available complexes.

Подробнее...

Печать E-mail

Synthesis and magnetic properties of cobalt ferrite nanoparticles in polycarbosilane ceramic matrix

Mössbauer spectra of the sample comprised of cobalt ferrite nanoparticles in a ceramic matrix after sintering in argon.Synthesis and magnetic properties of cobalt ferrite nanoparticles in polycarbosilane ceramic matrix. Yurkov G.Y., Shashkeev K.A., Kondrashov S.V., Popkov O.V., Shcherbakova G.I., Zhigalov D.V., Pankratov D.A., Ovchenkov E.A., Koksharov Yu.A. //Journal of Alloys and Compounds. 2016. V.686. P.421–430

Composite materials comprised of a ceramic matrix with metal-containing nanoparticles were prepared by sintering a blend of cobalt ferrite nanoparticles and polycarbosilane. Sintering process was performed either in air or argon, resulting in different material composition. The air-sintering materials consist mainly of oxide phases (silica matrix and cobalt ferrite nanoparticles). The process of sintering in argon leads to partial reduction of oxides and formation of α-Fe, carbide and silicate phases. The prepared samples were characterized by the SEM, TEM, XRD and EMR techniques and the Mössbauer spectroscopy. Static magnetic properties were also studied. All samples were found to be soft magnetic. Sintering, especially in argon, increases remnant magnetization of resulting composite products.

Подробнее...

Печать E-mail

Possibilities of cryogenic autoradiography

Characteristic curves obtained under different conditions: 1, at room temperature; 2, at the temperature of liquid nitrogen (experimental data, approximating straight lines of the regions of normal exposures, regions of photographic latitude, and inertia points are shown).

Possibilities of cryogenic autoradiography. Pankratov D.A., Korobkov V.I. //Journal of Analytical Chemistry. 2014. V. 69. Is. 7. P. 632–637Search the full text below. Ищи полный текст ниже.

Photographic properties of the nuclear photographic detector BioMax MR Film from KODAK are studied at the temperature of liquid nitrogen. The characteristic curves obtained at room and cryogenic temperatures indicate that the detector retains its physical and photographic properties, and its possibilities can be expanded to studies of deeply frozen samples. The data obtained point to an increase in the sensitivity of the photographic material frozen to cryogenic temperatures at short exposures.

Подробнее...

Печать E-mail

Electron paramagnetic resonance spectra near the spin-glass transition in iron oxide nanoparticles

Low-temperature EPR spectra in iron-oxide nanoparticles. HL and HR are left and right spectrum peaks, correspondingly.

Electron paramagnetic resonance spectra near the spin-glass transition in iron oxide nanoparticles. Koksharov Yu.A., Gubin S.P., Kosobudsky I.D., Yurkov G.Yu., Pankratov D.A., Ponomarenko L.A., Mikheev M.G., Beltran M., Khodorkovsky Y., Tishin A.M. //Physical Review B: Condensed Matter and Materials Physics. 2001. V. 63. № 1. P. 124071-124074Search the full text below. Ищи полный текст ниже.

Electron paramagnetic resonance (EPR) in iron-oxide nanoparticles (∼ 2.5 nm) embedded in a polyethylene matrix reveals the sharp line broadening and the resonance field shift on sample cooling below TF ≈ 40 K. At the same temperature a distinct anomaly in the field-cooled magnetization is detected. The temperature dependences of EPR parameters below TF are definitely different than those found for various nanoparticles in the superparamagnetic regime. In contrast to canonical bulk spin glasses, a linear fall-off of the EPR linewidth is observed. Such behavior can be explained in terms of the random-field model of exchange anisotropy.

Подробнее...

Печать E-mail

Materials on the same topic | Материалы по этой же теме

Яндекс.Метрика

Top.Mail.Ru
Top.Mail.Ru

http://www.youtube.com/RuRedOx