subject: What are Permanent Magnets and How do They Work? [print this page] What are Permanent Magnets and How do They Work?
A magnet is a well known material. Magnets can be manufactured artificially as well as they exist naturally in nature. A natural magnet is called as a permanent magnet and has its own magnetic field. A few elements which can hold the magnetic field can also be treated to act as permanent magnets. This list includes cobalt, iron, nickel and lodestone. These materials are termed as ferromagnetic materials. At high temperature, very powerful huge magnets are used to align the internal microcrystalline structure of these materials. Thus a new permanent magnet is produced from a ferromagnetic material. This alignment is so strong that the demagnetization is almost impossible. After the alignment process the ferromagnetic material stats repelling and attracting the magnetic materials depending on the magnetic field applied.
Cobalt, iron and nickel are used in the manufacturing of permanent magnets because these are ferromagnetic materials and have a natural tendency to hold the magnetism. The only thing is that in unmagnetized state their electrons posses unpaired spin. When magnetized properly the electrons get aligned in a special manner and this gives the material its magnetic property.
Dysprosium and Gadolinium are among those rare earth metals which can be converted into permanent magnets by changing their electron spins. Other rare earth elements can also act like permanent magnetic substances. These rare materials include samarium-cobalt, Neodymium alloy and the alloys made from naturally occurring elements like yttrium and scandium. The whole range of lanthanide elements is also used for this purpose.
There are many every day uses of permanent magnets. Attractive magnets used for holding the children?s achievements, is a common example which can be found in almost every home. Medical fiels also utilizes magnets. Many electronic appliances also need to have permanent magnets for the proper functioning of the device. The speakers of audio system require permanent magnets. In fact magnets are very important part of the speakers. It helps the conversion of signals into vibrations which carries sound. The electric energy is converted to sound energy by the coil of the magnet. Then this coil ultimately transfers the sound energy to the speaker. Microphones as well as the speaker phones both work on the same principle.
Generators as well as motors are another big area of utilization of magnets. Huge magnets are used to generate electricity at hydroelectric power station. Actually the stored water at the dams is fallen on the turbines at the power station. Due to the kinetic energy of water the turbines rotate and these turbines are connected to the coils. These coils rotate in huge magnetic frames. Due to the magnetic fields around, these rotating coils produce electric current. This electricity is then supplied to the power stations. Thus magnets play a vital role in our day to day life.
