Which description correctly defines diamagnetic materials?

Which description correctly defines diamagnetic materials?

• A. Substances that can become magnetized; iron, nickel & cobalt. Their atoms will form magnetic domains
• B. All electrons are paired; align perpendicularly to magnetic field lines, do not retain magnetic properties when the external magnetic field is removed
• C. Align parallel to magnetic field lines, and retain magnetization after the external field is removed
• D. Materials that have no interaction with magnetic fields

Answer: (B)

Diamagnetic materials respond to an external magnetic field by creating a tiny induced magnetic moment that opposes the field, and they have no permanent magnetization once the field is removed. This happens because all electrons are paired, so there are no unpaired spins to produce a lasting magnetic moment. The induced moment opposes the applied field, giving a weak repulsion, and when the external field is gone, the induced moment vanishes. In contrast, materials with magnetic domains that can be aligned and retain magnetization describe ferromagnetic behavior, and descriptions of moments aligning with the field and remaining afterward point to permanent magnets. The notion of no interaction at all with magnetic fields isn’t accurate, since diamagnetic materials do interact—just very weakly.

Diamagnetic materials respond to an external magnetic field by creating a tiny induced magnetic moment that opposes the field, and they have no permanent magnetization once the field is removed. This happens because all electrons are paired, so there are no unpaired spins to produce a lasting magnetic moment. The induced moment opposes the applied field, giving a weak repulsion, and when the external field is gone, the induced moment vanishes. In contrast, materials with magnetic domains that can be aligned and retain magnetization describe ferromagnetic behavior, and descriptions of moments aligning with the field and remaining afterward point to permanent magnets. The notion of no interaction at all with magnetic fields isn’t accurate, since diamagnetic materials do interact—just very weakly.