Nuclear spin diffusion in the semiconductor TlTaS3

We report on a 203Tl and 205Tl nuclear magnetic resonance study of the chain ternary semiconductor TlTaS3. We show that spin-lattice relaxation in this compound is driven by two contributions, namely by interactions of nuclear spins with thermally activated carriers and with localized electron spins. The latter mechanism dominates at lower temperature; at that, our measurements provide striking manifestation of the spin-diffusion-limited relaxation regime. The experimental data obtained allow us to estimate the spin diffusion coefficient.Comment: 15 pages, 5 figure

Size-dependent properties of dithallium selenide

We report on size-dependent properties of dithallium selenide, Tl2Se. We have carried out a comparative nuclear magnetic resonance (NMR) study of Tl2Se nanorods and bulk samples, measuring NMR spectra and spin-lattice relaxation rate of 203Tl and 205Tl isotopes. Though bulk Tl2Se was reported to be a metal, the Korringa-like spin-lattice relaxation behavior is observed only at low temperatures and is transformed to an activation regime above ~200 K. This finding is interpreted assuming a two-band model in the semimetallic compound. Our measurements show significant difference in the Knight shift and indirect nuclear exchange coupling for the bulk and nanorod Tl2Se samples, reflecting noticeable distinction in their electronic structure. At that, Tl2Se nanorods are semiconductors and exhibit a characteristic activation behavior in the spin-lattice relaxation rate due to the thermal excitation of carriers to the conduction band. The obtained size dependence of the Tl2Se properties is interpreted in terms of the semimetal-semiconductor transformation due to the quantum confinement.Comment: 15 pages, 4 figure

Корреляционный анализ как метод генерации моделей в металловедении

The paper contains description of new developed software which is designed to construct and use of mathematical macromodels which make it possible to solve problems of metal science practice for the system «steel composition - technological parameters of heat treatment - properties».with high accuracy, rather quickly, without any additional experiments. The software is presented as MODEL GENERATION MULTICOR.Описано разработанное авторами программное обеспечение, предназначенное для создания и использования математических макромоделей, позволяющих решать задачи металловедческой практики для систем «состав стали - параметры технологии термообработки - свойства» с высокой точностью, скоростью, без дополнительных экспериментов. Описан пакет программ - генератор моделей Multicor

Effect of thickness on the piezoelectric properties of LiNbO3 films

The results were obtained using the equipment of Research and Education Center and the Center of collective use “Nanotechnology” of Southern Federal University

The influence of styles of family education on emotional-volitional sphere of the senior preschool children

The article discusses the style of family education as its most important characteristic, the most inherent ways of attitude of parents to a child, using certain means and methods of pedagogical influence, which are expressed in a peculiar manner of verbal circulation and interactio