|Přednášející||Jiří Petr, Pavel Mach|
|Cvičící||Jiří Petr, Pavel Mach|
Types and mechanizmus of polarization. Dielectric absorption. Electrical conductivity of insulators. Dielectrics in static electrical field. Dielectrics in time-dependent electrical field. Frequency dispersion of polymers. Thermal dispersion of polymers. Optical properties of dielectrics. Dielectrics losses. Electrical strength of insulators. Electrical properties of thin dielectrics films. Ageing of insulators. Properties of feroelectrics. Main and joined phenomena in dielectrics.
The student must first obtain a credit and only then can apply for the exam. Assesment methods and criteria linked to learning outcomes: Conditions for the course-unit credit: active participation in seminars and elaboration and defense of individual work.
Students will acquire basic information about dielectric materials for electrical engineering. It will deal with the behavior of dielectrics in both static and electrical fields, polarizations, losses in dielectrics and types of dielectrics by state and type of polarization. It also obtains information about thin dielectric layers and about dielectric aging.
1. Introduction into the physics of dielectrics. Permanent and induced. Types of polarization.
2. Polarization and dielectric constant.
3. Dipole moments. Polarizability. Polarization and energy. Internal field.
4. Non-polar dielectrics. Lorentz's field. Clausius-Massotti equation.
5. Polarization in gases. The dielectric properties of gases.
6. Polarization in liquids. The dielectric properties of liquids.
7. Polarization in solids chosen. The dielectric properties of solids.
8. The dielectric relaxation theory. Frequency and Time Domain.
9. The complex dielectric permittivity. Dielectric losses and dispersion. Cole-Cole diagram.
10. Frequency and temperature dispersion of polymers.
11. Electrical strength of insulators - gases, liquids, solids.
12. Manufacturing and electrical properties of thin ceramic films.
13. Ferroelectrics and their dielectric properties. Curie-Weiss law.
14. Aging of dielectrics.
1. Introduction to laboratory tasks. Safety.
2. Measurement of non-polar dielectric properties in dependence on temperature.
3. Measurement of polar dielectric properties in dependence on temperature.
4. Measurement of non-polar dielectric properties in dependence on frequency.
5. Measurement of polar dielectric properties in dependence on frequency.
6. Curie temperature determination for polar dielectrics.
7. Measurement of polar dielectric properties over Curie temperature.
8.-12. Assignment of individual work.
13. Presentation and defense of individual work.
 Tillar Shugg: Handbook of Electrical and Electronic Insulating Materials, IEEE Press, New York, 1996
 Gorur G. Raju: Dielectrics in Electric Fields, ISBN 0824708644, CRC, 2003