Electric polarization involves the defect centers in the dielectric

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SUMMARY

Electric polarization in dielectrics is significantly influenced by defect centers, which directly affect permittivity. In perovskite structures, polar impurity sites create strong dipoles that interact with the surrounding lattice, leading to pinned polarization through dipole-dipole interactions. This phenomenon has been extensively studied in terms of electrostatic, thermodynamic, and transport properties, particularly regarding defects like oxygen vacancies that enhance ionic conductivity. Research in this area is ongoing, with contributions from experts such as Prof. Alex Shluger at UCL.

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  • Understanding of electric polarization in dielectrics
  • Familiarity with perovskite structures and their properties
  • Knowledge of defect centers and their impact on material properties
  • Basic principles of thermodynamics related to materials science
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Materials scientists, physicists, and researchers focusing on dielectric properties and electric polarization in advanced materials.

Silicon
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I konw that the defect centers in a dielectric contribute to the electric polarization and thus affect the permittivity.If there is any microscopic theory can derivate the relationship between the defect centers and the permittivity?
 
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There certainly is. I'm not sure I can find good references on short notice.

Very often - for instance in perovskite structures - an impurity site can be very polar (mostly from electron capture). This strong, oriented dipole "pins" the polarization of the surrounding lattice (in the vicinity) by dipole-dipole interactions. This effect has been studied extensively, in terms of the electrostatic, thermodynamic (the free-energy gains an inhomogeneous strain-energy-like term) and transport (some defects, like oxygen vacancies, can lead to high ionic conductivity) properties of materials.
 
Silicon said:
I konw that the defect centers in a dielectric contribute to the electric polarization and thus affect the permittivity.If there is any microscopic theory can derivate the relationship between the defect centers and the permittivity?

Great question. This is an issue of serious research right now. I will refer you to the home page of Prof Alex Shluger of UCL. He is working in this field and he collaborates with my phd promotor who is working in ESR-caracterization (like Pb-centers,etc).

Here it is http://www.cmmp.ucl.ac.uk/~ayg/group/
Click on "research"

regards
marlon
 
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