Electret

Electret (formed of elektr- from "electricity" and -et from "magnet") is material that has been permanently electrically charged (polarised). The magnetic equivalent is a permanent magnet. Oliver Heaviside coined this term.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Polarised material consists of atoms or molecules with electric dipole moment. It can be produced by cooling down material composed of long molecule chains with electric dipole moment so that so-called domains are formed.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Electret materials have recently found commercial and technical interest. For example, they are used in one form of microphone.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Electricity: :Separate-but related articles are Electrical energy, and Electric power...

Magnet: A magnet is an object that has a magnetic field. The word magnet comes from the Greek "magnítis líthos" (μαγνήτης λίθος), which means "magnesian stone". Magnesia is an area in Greece (Now Manisa, Turkey ) where deposits o...

Electrically charged: REDIRECT Electric charge...