Dielectric Properties
Components
Capacitor
Charge-Storage Plate
Dielectric
Purpose
Increase Capacitance
Limit Capacitor Voltage
Dielectric Strength
Insulation
Charge Separation
Non-Conductive
Polarisation Mechanisms
Electronic P
Atomic/Ionic P
Dipole/Orientation P
Space Charge P
All dielectric materials
Small Charge Displacement
Small Polarisation Amount
Ion Displacement within crystal structure
Effect
Pyroelectricity
Piezoelectricity
Ferroelectricity
Non symmetrical molecules have permanent dipoles orient in electric field
Larger Charge Displacement
Higher Polarization
Random Space Charges
Cosmic Radiation
Thermal Deterioration
Fabrication Process
Dielectric Variables
Dielectric Constant
Ability to polarise & store energy of electric field
Temp
Electronic Polarisation insensitive
Orientation Polarisation dependent
Ionic Polarisation increases with temp
Ion Mobility
Charge Carrier Increase
Dielectric Strength
Capability of material to withstand electric field w/o breaking down
Materials
BaTiO3
High Dielectricity
Perovskite Crystal Structure
Piezoelectricity
Piezoelectricity
Pyroelectricity
Ferroelectricity
Electricity => Mechanical
Polarisation cause by temp
Spontaneous Polarisation
High Permettivity
Polarisation Orientation by Electric Field
Produce Hysteresis Loop btwn E and P