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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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Ferroelectrics in an electric field
Pavelka, Petr ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
The submitted thesis describes characteristics and use of ferroelectric materials which find their utilization in electrotechnical and electronics industry. The thesis is mainly aimed at their behaviour in the electrical field at various intensity. The method using an osciloscope is selected for measuring. For the main measuring in part of this thesis was produced experimental wafer with five samples which were subsequently mesuared. The VEE PRO program was used for creating of collecting datas for histeresis loop and it’s functionality was checked on wafer with five examples in measuring. During this measuring was also measured electric tension dependence of components of complex permittivity.
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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.
|
|
|
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.
|
|
|
Ferroelectrics in an electric field
Pavelka, Petr ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
The submitted thesis describes characteristics and use of ferroelectric materials which find their utilization in electrotechnical and electronics industry. The thesis is mainly aimed at their behaviour in the electrical field at various intensity. The method using an osciloscope is selected for measuring. For the main measuring in part of this thesis was produced experimental wafer with five samples which were subsequently mesuared. The VEE PRO program was used for creating of collecting datas for histeresis loop and it’s functionality was checked on wafer with five examples in measuring. During this measuring was also measured electric tension dependence of components of complex permittivity.
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