Rare earth permanent magnet can be classified into five types according to its operational principle, includes Lorentz Force Effect, Ampere’s Circuital Law, Faraday’s Law of Electromagnetic Induction, Coulomb’s Law for Magnetism and other magnetic effects. Actually, each operational principle has extremely widespread application area.

Lorentz Force Effect

Lorentz Force is the combination of electric and magnetic force on a point charge due to electromagnetic fields. Application areas contain microwave tube, cathode ray tube, particle accelerator, magnetic spectrometer and magnetron sputtering system.

a. Cathode Ray Tube

b. Magnetic Spectrometer

c. Magnetron Sputtering System

d. Particle Accelerator

Ampere’s Circuital Law

Ampere’s Circuital Law relates the integrated magnetic field around a closed loop to the electric current passing through the loop. Ampere’s Circuital Law can be applied to the permanent magnet motor, loudspeaker, voice coil motor, compass, gyroscope and accelerometer.

a. Compass

b. Permanent Magnet Motor

c. Loudspeaker

d. Voice Coil Motor

e. Gyroscope

Faraday’s Law of Electromagnetic Induction

Faradays’s Law of Electromagnetic Induction is a basic law of electromagnetism predicting how a magnetic field will interact with an electric circuit to produce an electromotive force. Related applications include the permanent magnet generator, eddy current brake, microphone and eddy current magnetic separator.

a. Permanent Magnet Generator

b. Microphone

c. Eddy Current Magnetic Separator

d. Eddy Current Brake

Coulomb’s Law for Magnetism

The mode of action of Coulomb’s Law for Magnetism contains two ways:

1. Attraction and repulse between magnetic poles: magnetic coupling, magnetic bearing and magnetic spring.

2. Attraction between magnetic field and ferromagnetic materials: Magnetic separation, magnetic fluid sealing and magnetic lifter.

a. Magnet Bearing

b. Magnet Coupling

c. Magnetic Lifter

d. Magnetic Fluid Sealing

Other Magnetic Effects

Interactions between magnetic field and different substances will generate different magnetic effects, such as Nuclear Magnetic Resonance Effect, Faraday Magneto-optic Effect, Ferromagnetic Resonance Effect, Magnetic Entropy Effect and Magneto Resistance Effect.

a. Magnetic Resonance Imaging

b. Optical Isolator

c. Optical Circulator