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Information × Registration Number 0209U008915, 0108U008061 , R & D reports Title 3. Controlling thermoelectric properties of crystals and thin film structures of bismuth-antimony solid solutions popup.stage_title Head Rogacheva Elena, Доктор фізико-математичних наук Registration Date 25-12-2009 Organization National technical university "Kharkiv polytechnic institute" popup.description2 Thermoelectric properties of crystals and thin films of Bi-Sb solid solutions depending on concentration of antimony, thickness of thin films, temperature and magnetic field were investigated. Conditions at which the maximum values of high figure of merit is achieved were determined and also the general conformity to laws and specific physical mechanisms which are responsible for formation of thermoelectric properties of crystals and law dimentional structures on the Bi-Sb based were defined. The objects of the research are crystals and thin films of bismuth-antimony solid solutions. The goal of the work is a search for new ways of controlling thermoelectric (TE) properties of Bi-Sb solid solutions. The research methods are X-ray diffractometry, optical and electron microscopy, photoelectronic spectroscopy, electron-probe analysis, measurements of mechanical, electrophysical, galvanomagnetic, and thermoelectric properties. Cast and pressed Bi-Sb polycrystals in the concentration range of 0-20 at. % Sb were prepared using different modes of heat treatment. Thin Bi-Sb films of different compositions with the layer thicknesses from 5 to 400 nm were grown by thermal evaporation in vacuum. All samples were characterized using different structural methods. It was established that the obtained crystals were homogeneous, and the composition of the thin Bi-Sb layers corresponded to the composition of the charge used. The influence of the composition, doping with tellurium, temperature, magnetic field, and film thickness on the properties of Bi-Sb was established. For the first time, in the concentration dependences of the properties of crystals and films in the concentration ranges of 0.5-1.5 and 2.5 - 3.5 at.% Sb, concentration anomalies of the properties, including TE power factor were observed and attributed to the manifestation of critical phenomena which accompany a transition of the percolation type from diluted to concentrated solid solutions as well as a phase transition into a gapless state. The influence of the classical and quantum size effects on TE properties of thin Bi-Sb films was established. On the basis of the performed complex of studies recommendations as to the optimization of composition, temperature, magnetic field, and film thickness for obtaining new materials based on Bi-Sb with high values of TE figure of merit are developed. The forecast as to the development of the research object consists in the implementation of the recommendations in the process of manufacturing of thermoelectric materials based on Bi-Sb solid solutions for using them in thermoelectric refrigerators. Product Description popup.authors Булатов Олександр Сергійович Водоріз Ольга Станіславівна Волобуєв Валентин Валентинович Гуревич Алла Михайлівна Добротворська Марія Вікторівна Дроздова Ганна Анатолівна Нащекіна Ольга Миколаївна Ольховська Світлана Іванівна Орлова Дар'я Сергіївна Пінегін Володимир Іванович Рогачова Олена Іванівна Сіпатов Олександр Юрійович Щуркова Наталія Василівна popup.nrat_date 2020-04-02 Close