A plastic magnet is a non-metallic magnet. The first one functioning at room temperature, the polymer PANiCNQ which is a combination of the two compounds emeraldine based polyaniline (PANi) and tetracyanoquinodimethane (TCNQ), was created by researchers at the University of Durham in 2004. PANi is a conductive polymer that is stable in air, when combined with the free radical forming TCNQ as an acceptor molecule it can mimic the mechanism of metallic magnets. The magnetic properties arise from the fully pi-conjugatednitrogen containing backbone combined with molecular charge transfer side groups. These properties cause the molecule to have a high density of localised spins that can give rise to coupling of their magnetic fields. When a polymer magnet is synthesized, the polymer chains need a long time to line up before displaying any notable magnetism. Plastic magnets could have uses in computer hardware and in medicine where the organic material is more likely to be biocompatible than its metallic counterpart. This material might also revolutionize refrigerator magnets which with this can be made entirely out plastic instead of having a metal magnet attached.
The permanent magnet family consists, in general terms, of non-rare earth permanent magnets and rare earth magnets.
Although non-rare earth magnets are used in the majority of these applications due to their economic cost, rare earth permanent magnets have many distinguishing characteristics, such as a large Maximum Energy Product, (one performance index for permanent magnets).
Ceramic magnets are composed of iron oxide, barium and strontium elements.
The plasticmagnet composition as claimed in claim 2 wherein the coating layer on the surface of the particles of the powder of a metallic or alloy magnet is formed of a combination of the phosphorus-containing compound, the organic dye compound and an organopolysiloxane compound.
The plasticmagnet composition as claimed in claim 3 wherein the coating layer on the surface of the particles of the powder of a metallic or alloy magnet is composed of an undercoating layer formed of the phosphorus-containing compound and an overcoating layer formed of the organopolysiloxane compound.
The plasticmagnet composition as claimed in claim 4 wherein the coating layer on the surface of the particles of the powder of a metallic or alloy magnet is composed of an undercoating layer formed of the phosphorus-containing compound and the organic dye compound and an overcoating layer formed of the organopolysiloxane compound.