Course detail

Non-destructive diagnostics and physics of dielectrics

FEKT-LNDDAcad. year: 2011/2012

The objective of the course is to provide a survey of methods dealing on one side with the localisation and description of defects and their experimental investigation and on another side with the behaviour of dielectrics in electric fields and with their applications. Main topics cover transport and stochastic processes, noise non-destructive spectroscopy, non-destructive diagnostics, reliability tests, physical nature of polarisation in dielectrics, polarisation mechanisms at the microscopic level, mathematical and physical description of dielectric polarisation, overview of dielectric systems currnetly used in electrical engineering.

Language of instruction

Czech

Number of ECTS credits

5

Mode of study

Not applicable.

Guarantor

doc. Ing. Vladimír Holcman, Ph.D.

Department

Department of Physics (UFYZ)

Learning outcomes of the course unit

After passing the course students should be able to distinguish between stationary and non-stationary processes, to understand physical mechanisms of noise and excess charge carrier transport and to design and determine reliability parameters of the device under test. Furthermore they should understand the nature of polarisation processes at the microscopic level including their mathematical description and staring from this background information they should be able to choose the most suitable dielectric ansd insulating material for the application concerned.

Prerequisites

The subject knowledge on the Bachelor´s degree level is requested.

Co-requisites

Not applicable.

Planned learning activities and teaching methods

Teaching methods depend on the type of course unit as specified in the article 7 of BUT Rules for Studies and Examinations.

Assesment methods and criteria linked to learning outcomes

Requirements for completion of a course are specified by a regulation issued by the lecturer responsible for the course and updated for every.

Course curriculum

Not applicable.

Work placements

Not applicable.

Aims

The subject is oriented on the description and determination of transport, relaxation and stochastic processes in solids. Students will learn the basic methods in reliability analysis, degradation and noise and dielectric spectroscopy.

Specification of controlled education, way of implementation and compensation for absences

The content and forms of instruction in the evaluated course are specified by a regulation issued by the lecturer responsible for the course and updated for every academic year.

Recommended optional programme components

Not applicable.

Prerequisites and corequisites

Not applicable.

Basic literature

Bryknar, Z.: Fyzika dielektrik, Ediční středisko ČVUT, Fakulta jaderná a fyzikálně inženýrská, 1. vyd., Praha, 1983

Recommended reading

Not applicable.

Classification of course in study plans

  • Programme EEKR-ML Master's

    branch ML-EVM , 1 year of study, summer semester, theoretical subject

  • Programme EEKR-CZV lifelong learning

    branch EE-FLE , 1 year of study, summer semester, theoretical subject

Type of course unit

 

Lecture

26 hod., optionally

Teacher / Lecturer

doc. Ing. Vladimír Holcman, Ph.D.
doc. Ing. Karel Liedermann, CSc.
prof. Ing. Pavel Koktavý, CSc. Ph.D.

Syllabus

Types of defects, surface and structural defects, methods of localisation, destructive and non-destructive defects and their identification
Identification of defects from transport characteristics, V-A characteristics v in forward and reverse direction, excess current, generation-recombination process, degradation
Fluctuation processes, noise spectral power density and its correlation with the type of defect, low-frequency noise as reliability and quality indicator, lambda parameter - mean time to failure and its quantification
Noise density in semiconductor devices, noise in homogenous structures and in thin-layer and thick-layer resistors
Partial discharges and noise in insulators and dielectrics, noise in capacitors
Noise in semiconductor lasers, alloy and FET transistors
RTS noise of semiconductor diodes with quantum holes and dots
Theory for the design of a concept of a non-destructive diagnostic test
Phenomenological description of the polarisation
Types of relaxation mechanisms in polymers, glasses and ceramic systems
Mathematical methods for the evaluation of dielectric data
Degradation processes and their observation and monitoring by dielectric methods
Major types of dielectric materials
Main fields of application of dielectric materials and criteria for the selection of dielectrics for individual applications

Fundamentals seminar

13 hod., optionally

Teacher / Lecturer

doc. Ing. Vladimír Holcman, Ph.D.

Syllabus

Basic mathematical tools for the description of fluctuation and transport phenomena, stationarity and ergodicity, momentuses at the time and probability level, correlation function, noise spectral density
Calculation of noise magnitude in individual circuit components, transformation of noise during the transmission of a signal through an electronic system
Elements of diagnostics - size of ensembles and credibility of results, determination of the noise type, calculation of the excess current and of the reliability parameters
Dipol moments of elementary structural units (chemical bonds, molecules) and their calculation, polarisability alfa for atomic and dipole polarisation
Calculation of the local field and trabsition to the ferroelectric state, calculation of the permittivity of dielectric materials from their structure
Transformation from the time domain to the frequency domain and vice versa, Debye model, calculation of the distribution of relaxation times, both analytically and numerically, Hamon approximation, fitting
Ionic polarizations and the calculation of ionic polarizability

Laboratory exercise

13 hod., optionally

Teacher / Lecturer

doc. Ing. Vladimír Holcman, Ph.D.
Ing. Tomáš Trčka, Ph.D.

Syllabus

Measurements of V-A characteristics of semiconductor devices and the determination of their parameters and excess currents
Measurements of the spectral density of a fluctuation (a stochastic process) by both analogue and digital methods
Analysis of noise types from the experimentally found curves
Experimental determination of the dipole moment of nitrobenzene
Measurement of charge and discharge currents of dielectrics and transformation of the time-domain results to the frequency domain via Hamon approximation
Measurement of frequency and temperature dependence of complex permittivity and analysis of the results, determination of the activation energy and co-operativity of the relaxation process