What is the cause for diamagnetism and other types of magnetism?

[SandeshPhy]

What is the cause for diamagnetism and other types of magnetism?

Is it related to Farady's law or quantum mechanical properties of matter?

 

[Drakkith]

See here: http://en.wikipedia.org/wiki/Magnetism#Quantum-mechanical_origin_of_magnetism

 

[SandeshPhy]

So how do identify easily that a molecule or atom is diamagnetic or paramagnetic or ferromagnetic?

 

[chrisbaird]

It's actually more complex than two sentences on physics forums can do justice to the subject. Each electron has intrinsic angular momentum (spin) which gives rise to a magnetic dipole moment, and orbital angular momentum depending on what state it is in inside the atom, which also gives rise to a magnetic moment. Add up all the magnetic effects of all the electrons in an atom and you can get a total magnetic moment. But you also have to take into consideration how the atoms bond with each to form a solid, because will effect their magnetic dipole's ability to respond to an applied field. Also, in responding to an applied magnetic field, the electron states change, which change their magnetic properties.

 

[sardar]

The cause for diamagnetism and other types of magnetism is multifaceted and involves both classical and quantum mechanical principles. Diamagnetism, which is the weak repulsion of a material by a magnetic field, is caused by the orbital motion of electrons within atoms. When a magnetic field is applied, the electrons in the material will experience a force that opposes the external field, resulting in the material exhibiting a weak magnetic field in the opposite direction. This effect is related to Faraday's law of electromagnetic induction, as the changing magnetic field induces a current in the material which creates its own magnetic field.

Other types of magnetism, such as paramagnetism and ferromagnetism, are caused by the spin and magnetic dipole moments of electrons. In paramagnetic materials, the individual magnetic moments of electrons align with the external field, resulting in a weak attraction to the field. Ferromagnetism, on the other hand, occurs when the magnetic moments of electrons align spontaneously, resulting in a much stronger attraction to the external field.

Quantum mechanical properties of matter also play a role in understanding magnetism. In quantum mechanics, electrons are described as having intrinsic spin, which contributes to their magnetic moment. The arrangement and interactions of electrons within a material determine its magnetic properties, and these interactions can be described using quantum mechanical models.

In conclusion, the cause for diamagnetism and other types of magnetism involves a combination of classical principles, such as Faraday's law, and quantum mechanical properties of matter. Understanding these underlying mechanisms is essential for understanding and predicting the behavior of magnetic materials.