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Study of ferroelectric materials
Kos, Lukáš ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This work is focused on the study of perovskite ferroelectric materials group and monitoring changes their dielectric parameters in temperature and frequency dependence Is described scrystallographic systems of barium titanate and their influence on material properties. The measured values are mathematically interpreted using the Curie – Weiss law and discussed about the influence of strontium titanite on important dielectric parameters.
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Preparation and properties of ferroelectric ceramic materials
Vykoukalová, Tereza ; Maca, Karel (referee) ; Částková, Klára (advisor)
The aim of the work was a processing of ceramic material based on BST for ferroelectric application. Wet chemical techniques based on precipitations and sol-gel methods with ultrasound, hydrothermal or mechanochemical treatment supporting deaglomeration and reducing particle growth were used for BST ceramic powder synthesis. Suitable powders were selected by the evaluation of particle morphology, size and agglomeration, from these powders BST bulk ceramic with defined phase composition and morphology applicable for ferroelectric applications was prepared. It was found, that the most suitable method for preparation of phase pure and nanosized BST powder was sol-gel synthesis with solvothermal treatment (200 °C/48 h). Ceramic with relative density of 85 % TD and with the average grain size of about 1, 22 µm was prepared by pressing and sintering of the powder synthesized by the sol-gel method.
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Preparation and properties of ferroelectric ceramic materials
Vykoukalová, Tereza ; Maca, Karel (referee) ; Částková, Klára (advisor)
The aim of the work was a processing of ceramic material based on BST for ferroelectric application. Wet chemical techniques based on precipitations and sol-gel methods with ultrasound, hydrothermal or mechanochemical treatment supporting deaglomeration and reducing particle growth were used for BST ceramic powder synthesis. Suitable powders were selected by the evaluation of particle morphology, size and agglomeration, from these powders BST bulk ceramic with defined phase composition and morphology applicable for ferroelectric applications was prepared. It was found, that the most suitable method for preparation of phase pure and nanosized BST powder was sol-gel synthesis with solvothermal treatment (200 °C/48 h). Ceramic with relative density of 85 % TD and with the average grain size of about 1, 22 µm was prepared by pressing and sintering of the powder synthesized by the sol-gel method.
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Study of ferroelectric materials
Kos, Lukáš ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This work is focused on the study of perovskite ferroelectric materials group and monitoring changes their dielectric parameters in temperature and frequency dependence Is described scrystallographic systems of barium titanate and their influence on material properties. The measured values are mathematically interpreted using the Curie – Weiss law and discussed about the influence of strontium titanite on important dielectric parameters.
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Crystal growth from low-temperature solutions - theory and experiments
Novotný, Jan
Growth of crystals from low-temperature solutions belong to extended methods to acquire of high quality single crystals. Presented work reports the basic theories of crystal growth from solutions and shows their applications to optimization of crystal qrowth conditions where goal is preparation of high quality of single crystals. Next are shown experimental results of preparation of optical non-linear crystals for optoelectronics obtained at crystal growth laboratory of IREE AS CR.
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