diamagneetille

Diamagneetille is a phenomenon where a material is weakly repelled by an external magnetic field. This repulsion occurs because the magnetic field induces a temporary magnetic dipole moment in the material, which opposes the applied field. All materials exhibit diamagnetism, but it is often masked by stronger magnetic effects like paramagnetism or ferromagnetism. In diamagnetic materials, the electron orbitals within the atoms respond to the external field. When a magnetic field is applied, it changes the orbital motion of electrons, creating a magnetic field that points in the opposite direction to the applied field. This induced field is very weak.

The strength of diamagnetism is characterized by a negative magnetic susceptibility, denoted by the Greek letter chi ($\chi$). This value is typically very small, in the range of -10$^{-5}$ to -10$^{-6}$. Materials like water, bismuth, copper, and most organic compounds are diamagnetic. Superconductors exhibit perfect diamagnetism, meaning they expel all magnetic field lines from their interior, a phenomenon known as the Meissner effect. Diamagnetic levitation is a demonstration of this weak repulsion, where a small diamagnetic object can be levitated above a strong magnet. This effect is temperature-independent.