Understanding Magnetism: Debunking the Myth of All Matter Being Magnetic

[darkchild]

I was under the impression that everything was at least slightly, even if imperceptibly, magnetic because all matter that is not at absolute zero contains currents in the form of electron movement within its atoms. Is this correct?

 

[tiny-tim]

hi darkchild!

Yes, that's basically correct, but I don't think it has anything to do with currents of electrons.

All materials are slightly diamagnetic, and all materials (I think) with unpaired electrons are paramagnetic.

Diamagnetism comes from the dipoles of paired electrons (paired either between two atoms or within one atom … see http://en.wikipedia.org/wiki/Electron_pair" ), and is weakly present in all materials. Diamagnetic materials are repelled by magnetic fields, and lines of magnetic flux curve away from them.

From http://en.wikipedia.org/wiki/Diamagnetism" …

Diamagnetism is a very general phenomenon, because all paired electrons, including the electrons of an atom, will always make a weak contribution to the material's response. However, for materials that show some other form of magnetism (such as ferromagnetism or paramagnetism), the diamagnetism is completely overpowered. Substances that mostly display diamagnetic behaviour are termed diamagnetic materials, or diamagnets. Materials that are said to be diamagnetic are those that are usually considered by non-physicists to be "non-magnetic", and include water, wood, most organic compounds such as petroleum and some plastics, and many metals including copper, particularly the heavy ones with many core electrons, such as mercury, gold and bismuth.
… the term "diamagnetism" was coined by Michael Faraday in September 1845, when he realized that all materials in nature possessed some form of diamagnetic response to an applied magnetic field.​

Paramagnetism comes from the dipoles of unpaired electrons, and paramagnetic materials are attracted by magnetic fields … see http://en.wikipedia.org/wiki/Paramagnetism" .

 

[netheril96]

hi darkchild!

Yes, that's basically correct, but I don't think it has anything to do with currents of electrons.

All materials are slightly diamagnetic, and all materials (I think) with unpaired electrons are paramagnetic.

Diamagnetism comes from the dipoles of paired electrons (paired either between two atoms or within one atom … see http://en.wikipedia.org/wiki/Electron_pair" ), and is weakly present in all materials. Diamagnetic materials are repelled by magnetic fields, and lines of magnetic flux curve away from them.

From http://en.wikipedia.org/wiki/Diamagnetism" …

Diamagnetism is a very general phenomenon, because all paired electrons, including the electrons of an atom, will always make a weak contribution to the material's response. However, for materials that show some other form of magnetism (such as ferromagnetism or paramagnetism), the diamagnetism is completely overpowered. Substances that mostly display diamagnetic behaviour are termed diamagnetic materials, or diamagnets. Materials that are said to be diamagnetic are those that are usually considered by non-physicists to be "non-magnetic", and include water, wood, most organic compounds such as petroleum and some plastics, and many metals including copper, particularly the heavy ones with many core electrons, such as mercury, gold and bismuth.
… the term "diamagnetism" was coined by Michael Faraday in September 1845, when he realized that all materials in nature possessed some form of diamagnetic response to an applied magnetic field.​

Paramagnetism comes from the dipoles of unpaired electrons, and paramagnetic materials are attracted by magnetic fields … see http://en.wikipedia.org/wiki/Paramagnetism" .

Paramagnetism and diamagnetism describes how something responds to an external magnetic field,but what darkchild asks is whether all matter generates magnetic field itself

The answer should be no,because the movement of electrons is random and hence their magnetic moment normally will be canceled out.

By the way,how do you guys refer to the first one to post in a thread?I'm a Chinese,not familiar with slang.

 

[darkchild]

I was thinking that all material is magnetic (responds to a magnetic field) because electron orbits are tiny currents, and magnetic fields exert forces on currents.

 

[darkchild]

By the way,how do you guys refer to the first one to post in a thread?I'm a Chinese,not familiar with slang.

We call it the original poster, abbreviated OP on some forums, but I haven't seen it used much here.

 

[netheril96]

I was thinking that all material is magnetic (responds to a magnetic field) because electron orbits are tiny currents, and magnetic fields exert forces on currents.

Well,it seems to be I who misunderstood you.
Everything does respond to external magnetic fields