Magnet:-Property of Attraction by;-)#awesomeboy_atulraj
What inside a magnet gives it it's property of attraction? by;-)awesomeboy_atulraj
Magnets work because of the quantum mechanical property of Electrons.
In the atomic level, all material contains protons and electrons. Each of these fundamental particles are magnets on their own. Especially the electron, has a fundamental property of dipole-moment, other than bearing a charge, that makes it a small magnet. In the same sense, a proton is a small magnet too, but not as powerful as the electron is.
The dipole moment, which makes the electron behave like a magnet, is in turn, a consequence of an even more fundamental property called spin. The spin, being a quantum property, can exist in only two states, resulting in either up or down pointing magnetic fields. This is most contributing property as to why magnets are magnetic .
In an atom, the electrons are whizzing around, but confined in shells. These shells can be either half-filled or fully-filled depending upon the element. Generally, electrons form pairs, to cancel out their spins. In a pair, one electron would spin up, while the other would spin down, and thus, the net magnetic dipole-moment would be zero. So, atoms with fully-filled shells would not have a magnetic field of its own. These include atoms of mercury, gold, etc.
Coming to half-filled shells, the electrons would not pair up, resulting in a net magnetic field, as cancellation doesn't happen. The atoms of Iron, Cobalt, etc. show this behaviour, making them potentially a magnet.
These atoms are magnetic on their own, because of their electrons. However, when molecules/compounds are made, there is no guarantee that the resuting solid would be magnetic. This is because, in the formation of the solid, the groups of atoms may or may not all align in the same direction, in which case a magnet is created.
Now, let us understand the concept of magnetic domains. These are certain "areas" in a material that possess a net magnetic field, because the atoms are aligned in the same direction. Each of these domains, however, can be aligned in any direction. In this case, when the domains are randomly aligned, even though the individual atoms possess magnetic fields, the resulting solid would not behave like a magnet. This is because, for every domain, there would be another domain that would be aligned in the opposite direction, cancelling the magnetic fields. Pairing occurs in this randomness.
However, each of these domains react to an external magnetic field. And when they do, the individual atoms in a domain align themselves along the external field. Eventually, all the domains would be pointing along the same direction. The minuscule magnetic fields of the atoms would now aggregate to a stronger field. This property is shown by Ferromagnetic materials. Iron (Fe) lives up to its name. All ferromagnetic materials behave like magnets once they are influenced by an external magnetic field.
The actual question if the material remains permanently magnetized or not. This depends on whether the material is a hard ferromagnet or not. Meaning, the influence of an external magnetic field should be strong enough for the domains to stay oriented in the same direction. Most common ferromagnets are Iron, Cobalt, etc.
Now why does magnets attract?
I've explained why magnetic field exists, but why do they attract/repel other magnetic fields? Well, when fields of the opposite direction is present, they tend to come together because it keeps them in the least possible energy state, that is, the magnetic fields are weakened.
Yes, everything in nature is lazy...they seek the least energy state possible.
[1] Since the electron orbits around the nucleus of the atom, there would be small contributions to the magnetic field because of orbital magnetic fields., but they are too small to consider.
[2] According to Hund's rule: orbitals of the same energy are each filled with one electron before filling any with a second. Meaning, first, they would occupy single, and then start pairing up
In the atomic level, all material contains protons and electrons. Each of these fundamental particles are magnets on their own. Especially the electron, has a fundamental property of dipole-moment, other than bearing a charge, that makes it a small magnet. In the same sense, a proton is a small magnet too, but not as powerful as the electron is.
The dipole moment, which makes the electron behave like a magnet, is in turn, a consequence of an even more fundamental property called spin. The spin, being a quantum property, can exist in only two states, resulting in either up or down pointing magnetic fields. This is most contributing property as to why magnets are magnetic .
In an atom, the electrons are whizzing around, but confined in shells. These shells can be either half-filled or fully-filled depending upon the element. Generally, electrons form pairs, to cancel out their spins. In a pair, one electron would spin up, while the other would spin down, and thus, the net magnetic dipole-moment would be zero. So, atoms with fully-filled shells would not have a magnetic field of its own. These include atoms of mercury, gold, etc.
Coming to half-filled shells, the electrons would not pair up, resulting in a net magnetic field, as cancellation doesn't happen. The atoms of Iron, Cobalt, etc. show this behaviour, making them potentially a magnet.
These atoms are magnetic on their own, because of their electrons. However, when molecules/compounds are made, there is no guarantee that the resuting solid would be magnetic. This is because, in the formation of the solid, the groups of atoms may or may not all align in the same direction, in which case a magnet is created.
Now, let us understand the concept of magnetic domains. These are certain "areas" in a material that possess a net magnetic field, because the atoms are aligned in the same direction. Each of these domains, however, can be aligned in any direction. In this case, when the domains are randomly aligned, even though the individual atoms possess magnetic fields, the resulting solid would not behave like a magnet. This is because, for every domain, there would be another domain that would be aligned in the opposite direction, cancelling the magnetic fields. Pairing occurs in this randomness.
However, each of these domains react to an external magnetic field. And when they do, the individual atoms in a domain align themselves along the external field. Eventually, all the domains would be pointing along the same direction. The minuscule magnetic fields of the atoms would now aggregate to a stronger field. This property is shown by Ferromagnetic materials. Iron (Fe) lives up to its name. All ferromagnetic materials behave like magnets once they are influenced by an external magnetic field.
The actual question if the material remains permanently magnetized or not. This depends on whether the material is a hard ferromagnet or not. Meaning, the influence of an external magnetic field should be strong enough for the domains to stay oriented in the same direction. Most common ferromagnets are Iron, Cobalt, etc.
Now why does magnets attract?
I've explained why magnetic field exists, but why do they attract/repel other magnetic fields? Well, when fields of the opposite direction is present, they tend to come together because it keeps them in the least possible energy state, that is, the magnetic fields are weakened.
Yes, everything in nature is lazy...they seek the least energy state possible.
[1] Since the electron orbits around the nucleus of the atom, there would be small contributions to the magnetic field because of orbital magnetic fields., but they are too small to consider.
[2] According to Hund's rule: orbitals of the same energy are each filled with one electron before filling any with a second. Meaning, first, they would occupy single, and then start pairing up
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