Explain in detail about the types of magnetism, for e.g. - ferromagnet, paramagnet and diamagnet. Explain their uses also in detail.
We have made a science model and we have used ferromagnet in it. If the judges asked why have we used that, then please tell the reasons also.
Note - Explain in a easy language as far as possible.
No spamming.
Answers
Magnetism: Physical Phenomena that are related to magnetic field.
Pics are taken from :Wikimedia (Non-Copyrighted images) and other two made by Paint:
Magnetic Classification of substances (according to magnetic behaviour) :
1) Diamagnetic Substances : (see pic 4)
=> Substances which are weakly repelled away from the magnet when brought close to a powerful magnet .
=>These Substances are faintly magnetised when opposite to the direction of magnetic field when placed in an external magnetic field.
=> They have tendency to move from stronger to the weaker part of magnetic field . (SEE PIC
)
=>Unlike,the way magnet attract metals like iron ,it would repel a diamagnetic substance .
Examples of diamagnetic substances : Bismuth,Zinc,Copper ,Silver ,gold,Lead,Water ,Hydrogen,etc.
2)Paramagnetic Substances: (see pic 3)
=> Substances which are weakly magnetised when placed in an external magnetic field .
=> They have tendency to move from a region of weak magnetic field to strong magnetic field ,i.e. they get weakly attracted to a magnet .
(see pic )
=> The individual atoms (ions or molecules) of paramagnetic material dipole posses a permanent magnetic dipole moment of their own .
Examples : Aluminium , Oxygen , Titanium ,Iron Oxide,etc,
3) Ferromagnetic : (see pic 1,2)
=> Substance which are strongly magnetised when placed in an external field .
=> They have strong tendency to move from a region of weak magnetic to strong magnetic field ,i.e, they get strongle attracted to a magnet .
=> The individual atoms (or ions or molecules) in a ferromagnetic material
posses a dipole moment,same as in paramagnetic material .
=> However, they interact with one -another in such a way that they spontaneously align themselves in a common direction over a macroscopic small volume .
=> When we apply an external magnetic field ,the domains orient themselves in the direction of that magnetic field .
For Example: Iron,Cobalt,Nickel,etc.
See pics:
Uses of Magnetic Materials: ( I am gving uses which are generally un-known ,however there are manY )
1) In Compact Hard-drives ,Ferro-magnetic materials are used to form a real around a rotating shaft .
2) In auto-mobiles ,Magnetic materials are used in brakes ,high -performance shock-absorbers, for civil engineering (construction sites) ,industries ,household appliances
.
3) Medicinal Use :
Carrying Medications to exact location within the body and aslo as contrasting agent in MRI scans.
Magnetism is defined as an attractive and repulsive phenomenon produced by a moving electric charge. The affected region around a moving charge consists of both an electric field and a magnetic field. The most familiar example of magnetism is a bar magnet, which is attracted to a magnetic field and can attract or repel other magnets.
hese types of magnetism are: ferromagnetism, ferrimagnetism, antiferromagnetism, paramagnetism, and diamagnetism.
Ferromagnetism and ferrimagnetism occur when the magnetic moments in a magnetic material line up spontaneously at a temperature below the so-called Curie temperature, to produce net magnetization. The magnetic moments are aligned at random at temperatures above the Curie point, but become ordered, typically in a vertical or, in special cases, in a spiral (helical) array, below this temperature. In a ferromagnet, magnetic moments of equal magnitude arrange themselves in parallel to each other. In a ferrimagnet, on the other hand, the moments are unequal in magnitude and order in an antiparallel arrangement. When the moments are equal in magnitude and ordering occurs at a temperature called the Neel temperature in an antiparallel array to give no net magnetization, the phenomenon is referred to as antiferromagnetism. These transitions from disorder to order represent classic examples of phase transitions. Another example of a phase transition is the freezing of the disordered molecules of water at a critical temperature of 32°F (0°C) to form the ordered structure of ice. The magnetic moments—referred to as spins—are localized on the tiny electronic magnets within the atoms of the solid. Mathematically, the electronic spins are equal to the angular momentum (the rotational velocity times the moment of inertia) of the rotating electrons. The spins in a ferromagnetic or a ferrimagnetic single crystal undergo spontaneous alignment to form a macroscopic (large scale) magnetized object. Most magnetic solids, however, are not single crystals, but consist of single crystal domains separated by domain walls. The spins align within a domain below the Curie temperature, independently of any external magnetic field, but the domains have to be aligned in a magnetic field in order to produce a macroscopic magnetized object. This process is effected by the rotation of the direction of the spins in the domain wall under the influence of the magnetic field, resulting in a displacement of the wall and the eventual creation of a single large domain with the same spin orientation.