Application of magnetic materials

☆  Electrical motor and generator ☆

》 As the electric motor Electromegtets  in the spinning stator to turn . There is an electrically slippring  on the stator that directs the power to a different magnet section of the stator to achieve rotation Quick

☆Magnetic Storage ☆

》 Magnetic storage ifs magnetic recording are terms from engineering referrinv to the storage of data on a magnetized medium . Magnetic storage uses different patterns of magnetizing in a magnetizable material to store dtat and is a form of non volatile . The information access using one and more real wire head

☆Magnetic Bearing☆

》A magnetic bearing is a bearing which support a load using magnetic leviation . Magnetic bearing support moving machinery without physical contact for axample they can leviate a rotating shaft and permit leviate motion with very low friction load no mechanical wear .

☆Magnetic Resonance Image MRI☆

》A magnetic resonance algorithm is a type of magnetic resonance imaging scan that uses a magnetic field and pulses of ratio wave energy to provide picture of blood vessels inside the body . In many case MRI can provide information that can not be obtained from a x-rays ultrasound and computed tomography scan.

☆Eddy Current ☆

》 Eddy current brake like a conventional friction brake , is responsible for slowing object, as a train or a roller coaster . However unlike electromechanical brakes, which apply mechanical pressures on two separate objects eddy current brake slow an object by creating eddy current through electromagnetic induction which create resistance and turn it  either heat or electricity

Types of magnetism

☆ Diamagnetism
☆ Paramagnetsim
☆ Feromagnetsim
☆ Antiferromagnetsim

■ Diamagnetsim

• Diamagnetsim is a fundamental property of all matter, although it is usually very week. It is due to non co-operative behaviour of obtaining electrons when exposed to an applied magnetic field . Diamagnetic substance are compund of atoms which have no net magnetic moment . however when exposed to a filed .If we plot M vs H we see

■ Paramagnetism

• This class of material some of the atoms are ions in the material have a net magnetic moment due to unpaired electron in partially filled orbit . Once of the most important atoms with unpaired electrons in iron . However the individual magnetic moment do not interact magnetically, and like diamagnetism , the magnetization is zero when the field is removed . In the presence of the field there is now a partial alignment of the atomic magnetic moment in the direction of the filed resulting in a net positive magnetism and positive susceptibility

■ Ferromagnetism

When tou think magnetic materials, you probably think iron nickel or magnetic . Unlike paramagnetic materials, the atomic.moment is that materials exhibit very strong interactions. These interaction produce by electronic exchange force and result in a parallel or anti parallel alignment of atomic moment . Exchange fore are very large equivalent to a filed on the order of 1000Tesla or approximately a 100million times the strength of the earth field.

■ Antiferromagnetism
• The material moment of atoms or molecules usually to the spin of electron align in a regular pattern with neighbouring spins pointing in opposite direction . This is like ferromagnetism ,a manifestation of ordered magnetsim . Generally antiferromagnetic order may exist at sufficiently low temperature ., vanishing at and above a certain temp.The tempreature above the Neel temperature the material is typically paramagnetic.

☆Applications

•  Eletro motor ange generator
•  Magnetic storage
• Magnetic bearing
• Magnetic separator
• Medical appliance
• Magnetic Resonance Imaging MRI
• For security purpose
•Eddy current brake

Magnetic material and its properties

Magneticmaterial and its properties

》It is a common characteristics of materials . Magnetic properties of a material involve concept based on the magtnetic dipole moment . Soke of the material have the ability to create internal dipole moment . for this reason this kind of material present cpecial type of properties.

• Attracting other magnetic material.
• Inducing pole in this material.
• The polarity of teo pole are opposite
• When magnetizing occuring then some parameter of material is changed ( current I, Magnetic flux)

☆Magnetic moment :

• A vector quantity associated with the magnetic properties of electric current loops or, more generally magnets . It is equal to the amount of current flowing through the loop multiplied by the area encomlossed  by the loop, and its direction is established by the Right hand rule for rotations

☆Magnetic field or intensity ☆

• A field of force associated with changing electric fields, as when electric charge are in motion . Magnetic field exert defective force on moving electric charges.
• Most magnet have magnetic field as a result of the spinning motion of the electrons orbiting the atoms of which they are composed.
electromagnet create such field from electric current moving through coils

   ☆Magnetic Susceptibility ☆

• In electromagnetisim the magnetic susceptibility Xm is demensionless proportionally constant that indicate degree of magnetization of a material in responsee to an applied magnetic field

M=xH

                 ☆Hystersis☆

• In addition to the curie temperature and saturation magnetization ferromagnetism can retain a memory of an applied field once it is removed
 this behaviour is called Hystersis and a plot of the variation of magnetization with magnetic field is called hystersis loop

              ☆Curie Temperature☆

• Even though electronic exchange  force  in ferromagnets are very large , thermal energy eventually overcome the exchange and produce a rendomizing effect . This occur at a particular temperature called curie temperature Tc . Below the curie temperature the ferromagnet is ordered and above it, disordered. The saturation magnetization goes to zero at the curie temp. A typical plot of magnetization vs temp. for magnetic is shown below