Litteris et Artibus
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Item Positron annihilation lifetime spectroscopy in application to nanostructured glasses and ceramics(Видавництво Львівської політехніки, 2017-12-23) Klym, Halyna; Kostiv, Yuriy; Lviv Polytechnic National UniversityModified nanostructured Ge-Ga-Se chalcogenide glasses and oxide MgO-Al2O3 ceramics were investigated using positron annihilation lifetime spectroscopy. It was shown that crystallization process in 80GeSe2-20Ga2Se3 glasses annealed at 380°C for 25 and 50 h indicates specific free-volume transformation. It is established that water vapor modifies defects located near grain boundaries in MgO-Al2O3 ceramics sintered at 1300 °C, the process being accompanied by void fragmentation at water adsorption with further void agglomeration at water desorption after drying.Item Electrical properties of singleand multi-walled carbon nanotubes composites at low temperatures(Видавництво Львівської політехніки, 2017-12-23) Karbovnyk, Ivan; Lukashevych, Dmytro; Chalyy, Dmytro; Klym, Halyna; Ivan Franko National University of Lviv; Lviv State University of Life SafetyElectrical properties of single- and multi-walled carbon nanotubes composites (PEDOT:PSS/CNTs) were investigated in the range of 50 to 200 K. It is established that composite films with multi-walled nanotubes loading show lower resistances as compared to their single-walled counterpart.Item Combined thick-film structures based on modified nanoceramics for sensor electronics(Lviv Polytechnic Publishing House, 2016) Klym, Halyna; Kostiv, Yuriy; Lviv Polytechnic National UniversityCombined temperature and humidity sensitive thick-film structures based on technological modified nanostructured ceramics (Cu0.1Ni0.1Co1.6Mn1.2O4 with p+-type of electrical conductivity, Cu0.1Ni0.8Co0.2Mn1.9O4 with p-type of electrical conductivity and magnesium aluminate i-type MgO-Al2O3), as well as temperature-sensitive p-p+ and p-p+-p structures were prepared and studied. It is shown that increasing of the quantity of thick-film layers results in the improvement of the temperature sensitivity of thick-film structures. Humidity-sensitive thick films with temperature-sensitive films as conductive layers posses linear dependence of electrical resistance on relative humidity with hysteresis in the range of 30-95 %.