Ferrite Disc Magnets for holding devices

Permanent Ferrite Magnet for holding devices

Barium hexaferrite (BaO•6Fe2O3) was discovered in 1950 at the Philips Natuurkundig Laboratorium (Philips Physics Laboratory). The discovery was somewhat accidental—due to a mistake by an assistant who was supposed to be preparing a sample of hexagonal lanthanum ferrite for a team investigating its use as a semiconductor material. On discovering that it was actually a magnetic material, and confirming its structure by X-ray crystallography, they passed it on to the magnetic research group.Barium hexaferrite has both high coercivity (170 kA/m) and low raw material costs. It was developed as a product by Philips Industries (Netherlands) and from 1952 was marketed under the trade name Ferroxdure.The low price and good performance led to a rapid increase in the use of permanent magnets.

In the 1960s Philips developed strontium hexaferrite (SrO•6Fe2O3), with better properties than barium hexaferrite. Barium and strontium hexaferrite dominate the market due to their low costs. Other materials have been found with improved properties. BaO•2(FeO)•8(Fe2O3) came in 1980.and Ba2ZnFe18O23 came in 1991.

characteristic: 
The powder metallurgy method has low remanence and low recovery magnetic permeability. High coercivity, strong anti-demagnetization ability, especially suitable for dynamic working conditions of magnetic circuit structure. Hard and brittle material, can be used for emery tools for cutting processing. The main raw material is oxide, so it is not easily corroded. Operating temperature :-40℃ to +200℃. 
Ferrite magnets are divided into anisotropic (heterotropic) and isotropic (isotropic). The magnetic properties of the isotropic sintered ferrite materials are weak, but they can be magnetized in different directions of the magnet. Heteromorphic sintered ferrite Permanent Magnet materials have strong magnetic properties, but only along the intended direction of magnetization of the magnet. 

Hard Ferrite Magnet have high coercivity, so are difficult to demagnetize. They are used to make permanent magnets for applications such as refrigerator magnets, loudspeakers, and small electric motors.

The main performance and grade parameters of Ferrite Permanent Magnets