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

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

Electronic properties and phase transitions in low-dimensional semiconductors

We present the first review of the current state of the literature on electronic properties and phase transitions in TlX and TlMX2 (M = Ga, In; X = Se, S, Te) compounds. These chalcogenides belong to a family of the low-dimensional semiconductors possessing chain or layered structure. They are of significant interest because of their highly anisotropic properties, semi- and photoconductivity, non-linear effects in their I-V characteristics (including a region of negative differential resistance), switching and memory effects, second harmonic optical generation, relaxor behavior and potential applications for optoelectronic devices. We review the crystal structure of TlX and TlMX2 compounds, their transport properties under ambient conditions, experimental and theoretical studies of the electronic structure, transport properties and semiconductor-metal phase transitions under high pressure, and sequences of temperature-induced structural phase transitions with intermediate incommensurate states. Electronic nature of the ferroelectric phase transitions in the above-mentioned compounds, as well as relaxor behavior, nanodomains and possible occurrence of quantum dots in doped and irradiated crystals is discussed.Comment: 70 pages, 38 figure

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

Развитие неопарсонсианства на рубеже XX-XXI в

The article is dedicated to the conceptualization of the innovations in the theories of T. Parsons at the turn of the XX-XXI centuries. It is stated the increased interest for structural functionalism in the development of sociological theory as well as in applied research. The article illustrates that the attempt of T. Parsons to create a system of categories enable to accept systematic integration of sociological science, explaining the existence of all the levels of the society and all the social forms in the process of movement of the matter, caused great interest among the scientists in the leading sociological centres of the world. The structurally-functionalist paradigm, associated with Parsons, was reflected in institutional imperatives of “ethnic science” by R. Merton, representation of science as a multilevel continuum, suggested by D. Alexander, in the conception/concept of “double contingency” by N. Luhmann, culture as a network of symbols by C. Geertz, the theory of communicative action by J. Habermas, in the theory of structuration by A. Giddens, the concept of the acting person by A. Touraine and etc.Статья посвящена осмыслению неопарсонсианстских теорий на рубеже XX-XXI столетий. Констатируется возросший интерес к структурному функционализму как в развитии социологической теории, так и в прикладных социологических исследованиях. Показано, что предпринятая Т. Парсонсом попытка разработать категориальную систему, допускающую систематическую интеграцию социологического знания, которое объясняло бы все уровни общества и все формы движения социальной материи, затронула ученых в ведущих социологических центрах мира. Ассоциируемая с Т. Парсонсом структурно-функционалитстская парадигма нашла свое выражение в институальных императивах “этоса науки” Р. Мертона, понимания науки как многоуровнего континуума Д. Александера, в концепции “двойной контингентности” Н. Лумана, культуры как сети символов К. Гирца, теории коммуникативного действия Ю. Хабермаса, теории структурации Э. Гидденса, концепции человека действующего А. Турена и др

Piezoceramic material based on PZT for use in actuators and hydroacoustics

Исследованы электрофизические и механические свойства сегнетомягкого пьезокерамического материала на основе ЦТС с Ec=6 кВ⁄см и TC=150°C. Полученные данные и пьезоэлектрические характеристики свидетельствуют о возможности применения данного материала для использования в актюаторах и гидроакустиких устройствах.The electrophysical and mechanical properties of a ferrosoft piezoceramic material based on a PZT with Ec = 6 kV/cm and TC = 150°C have een studied. The o tained data and piezoelectric characteristics testify to the possibility of using this material for use in actuators and hydroacoustics

Features of the properties of lead-free ferroelectric ceramic material TBK-3 in the region of phase transition

В работе исследована нелинейность диэлектрического отклика в сегнетопьезокерамике ТБК-3 в области фазового перехода.The nonlinearity of the dielectric response in TBK-3 ferroelectric piezoceramics in the region of the phase transition is studied