Reaction of Am(VI) with Na<Subscript>4</Subscript>XeO<Subscript>6</Subscript> in Alkaline Solutions in the Presence of Ozone

The reaction of Am(VI) with perxenate ions XeO ₆ ^4? in 1 M NaOH solutions was studied. A solid compound [Am(VI) : Na₄XeO₆ = 1 : 1] is formed in reaction of 1 mM Am(VI) with solid Na₄XeO₆; its ozonation in a thin layer yields an Am(VII) compound.     

Separation of Trivalent Americium and Rare-Earth Elements from Iron Impurity Using Certain Coordination Compounds

A procedure was developed for separation of trivalent Am and rare-earth elements from iron, involving stabilization of iron in the Fe(II) state with hydrazine nitrate in weakly acidic solution in the presence of dimethylglyoxime or bipyridine, followed by precipitation of f elements as hydroxides. With bipyridine used as a complexone, the iron content in the recovered and washed 4f and 5f element hydroxides does not exceed 10^?6 M.     

Analysis of characteristics of photodetectors based on InGaAs heteroepitaxial structures for 3D imaging

The 320 × 256 focal plane arrays based on р ⁺ -B–n-N ⁺ tetralayer heterostructures with a wide-gap barrier layer have been investigated. The heterostructures with a narrow-gap n-InGaAs absorbing layer were grown by means of metalorganic vapor phase epitaxy on InP substrates. The band discontinuity between the In_0.53Ga_0.47As absorbing layer and the In_0.52Al_0.48As barrier layer is removed by growing a thin four-component n-AlInGaAs layer with the bandgap gradient variation. Delta-doped layers included into the heterostructures make it possible to lower the barrier in the valence band and eliminate the nonmonotonicity of energy levels. The experimental study of the dark current has been performed. It has been revealed that the average value of the dark current does not exceed 10 fA for the photodiode arrays with a pitch of 30 μm.     

Multi-Row Photodetectors for the Short Wavelength IR Region Based on HgCdTe Heteroepitaxial Structures

Journal of Communications Technology and Electronics - Parameters of multi-row photodetectors (PDs) based on HgCdTe heteroepitaxial structures of different formats, including 288 × 4, 480...     

Effect of hydrogen peroxide on precipitation of Pu(IV) in alkaline solutions

Formation of peroxy compounds of Pu(IV) is possible in concentrated alkali solutions despite instability of hydrogen peroxide under these conditions. The resulting peroxy compound of Pu(IV) is fairly stable in alkaline solutions. The [Pu]: [O₂⁻] ratio in the compound is close to 1: 2. The formation of the peroxy compound favors a decrease in the content of colloidal polymeric Pu(IV) species in solution, thus making the Pu precipitation from solution more complete.     

Molecular dynamics simulation of copper bicrystal response to shear loading

The behavior of a large-angle grain boundary of the Σ = 5 (210)[001] special type in a copper bicrystal under shear loading conditions has been computer simulated. It is established that, simultaneously with the relative slippage of grains in the direction of applied load, the grain boundary shifts in the direction perpendicular to that of shear straining. This motion of the grain boundary exhibits a discrete character and leads to a growth of one grain at the expense of another. The mechanism of this displacement is analyzed and the influence of the loading rate and direction on the character of grain boundary motion is studied. The obtained results provide better understanding of the atomic mechanisms of plastic strain development in polycrystalline materials.     

Controlling graphite oxide bandgap width by reduction in hydrogen

Transformation of the chemical composition and electron structure of graphite oxide (GO) nanolayers as a result of their annealing in hydrogen has been studied by X-ray photoelectron spectroscopy using synchrotron radiation. It is established that both the chemical composition and bandgap width of GO can be controlled by varying the temperature and duration of heat treatment. By this means, the properties of GO nanolayers can be smoothly changed from dielectric to semiconductor.