Interfacial polarization, Physics

Interfacial polarization takes place whenever there is an storage of charge at an interface between two materials or between two regions in a material. As shown in the material has an equal number of positive ions and negative ions are assumed to be far more mobile. Under the presence of an applied field, these positive ions migrate to the negative electrode. The positive ions, however, cannot leave the dielectric and the crystal structure of the metal electrodes. They therefore simply pile up at the interface and give rise to a positive space charge in the bulk together constitute dipole moment that appear in the polarization vector p. The positive charge on the electrode, of course, appears as an increase in the dielectric constant. One of the typical examples of interfacial polarization is the grain boundaries that frequently lead interfacial polarization as they trap can charges migrating under the influence of an applied field. Dipoles between the trapped charges increase the polarization vector. Interfaces also arise in heterogeneous dielectric materials for example, when there is a dispersed phase within a continuous phase. The last three mechanisms are amenable to basic considerations and calculations, interfacial polarization, however, defines basic treatment. There is no general way to calculate the charges on neither interfaces nor their contribution to the total polarization of a material. Interface polarization is thus often removed from the discussion of dielectric properties. It would be completely wrong however to conclude that interface polarization is technically not significant because, on the one hand numerous dielectrics in real capacitors rely on interface polarization whereas, on the other hand, interface polarization if present may "kill" many electronic devices e.g. the MOS transistors. Normally interfacial polarization exists in the materials, however perfect, contain crystal defects, various mobile charge carries such as electrons (e.g.; from donor type impurities), holes or impurity ions or ionized host. H+ ion Li+ ion in ceramics and glasses are the general example of this type of polarization.

Posted Date: 7/7/2012 5:11:19 AM | Location : United States







Related Discussions:- Interfacial polarization, Assignment Help, Ask Question on Interfacial polarization, Get Answer, Expert's Help, Interfacial polarization Discussions

Write discussion on Interfacial polarization
Your posts are moderated
Related Questions
An ostrich can run at speeds of up to 72km/h. Suppose an ostrich runs 1.5km at the speed of 58 km/h and then runs another 1.5km at the speed of 29km/h. What is the ostrich average

A train locomotive whose mass is 1 x 106 kilograms is travelling EAST at a speed of 100 kilometers per hour.  A NORTHERLY wind is applying a force of 100 Newtons on the locomo

a boy jumps from height of 100m?what will be its velocity when it reaches ground?

A positively charged particle is pitiful southward in a downward-directed uniform magnetic field. The magnetic force is the merely force if any acting on the particle. What is the

Laplace equation (P. Laplace): For steady-state heat conduction in one dimension, the temperature distribution is the resolution to Laplace's equation, that states the second

why the direction of centripetal force isnot marked in diagram


Describe coefficient of self induction, coefficient of mutual induction. What types of transformer is used in a bed lamp.

The average speed of a substance in a given interval of time is explained as the ratio of the distance done to the time taken whereas; average velocity is explained as the ratio of

Micanite is a form of (A) Built up mica. (B) Hydrated potassium aluminium silicate. (C) Magnesium mica. (D) Calcium mica. Ans: Micanite is a form of Buil