Question about orbital and spin magnetic dipole

[SR_0301]

Hello guys, i want to ask you a question about orbital and spin dipole, and how this is going to influence diamagnetic or paramagnetic substances. So my question is: we know in a atom there is orbital and spin motion by electrons so possibly two magnetic dipoles. Is it correct to say that in diamagnetic substances, the spin dipole is equal and opposite to the orbital dipole, so when we provide a magnetic field we get induced magnetic dipole opposite to that magnetic field. And is it also correct to say that this is not going to show up in a paramegnetic substance because here spin dipole + orbital dipole is different from zero?

 

[Hyperfine]

See The Magnetism of Matter

That is Chapter 34 in The Feynman Lectures on Physics, Volume II. The website is hosted by Cal Tech.

 

[Meir Achuz]

Hello guys, i want to ask you a question about orbital and spin dipole, and how this is going to influence diamagnetic or paramagnetic substances. So my question is: we know in a atom there is orbital and spin motion by electrons so possibly two magnetic dipoles. Is it correct to say that in diamagnetic substances, the spin dipole is equal and opposite to the orbital dipole, so when we provide a magnetic field we get induced magnetic dipole opposite to that magnetic field. And is it also correct to say that this is not going to show up in a paramegnetic substance because here spin dipole + orbital dipole is different from zero?

Magnetism in diamagnetic materials is dominated by the intrinsic magnetic momentum of the electron spin.
A B field acting on this magnetic moment rotates it in the direction of B, so that mu is greater then one.
Magnetism in a paramagnetic material is caused by the field acting on the magnetic moment of the electron's orbital path. By Lenz's law, this rotates the dipole moment away from the direction of the B field, so that mu is less then one.