Curietörvényt

Curietörvényt, often translated as Curie's Law, describes the magnetic susceptibility of certain materials as a function of temperature. Specifically, it applies to paramagnets and ferromagnets above their Curie temperature. The law states that the magnetic susceptibility of a paramagnetic material is inversely proportional to the absolute temperature. In mathematical terms, this is expressed as $\chi = \frac{C}{T}$, where $\chi$ is the magnetic susceptibility, $T$ is the absolute temperature, and $C$ is the Curie constant, a material-specific parameter.

This relationship was formulated by Pierre Curie. For paramagnets, the individual magnetic moments of atoms or molecules tend to align with an external magnetic field, but thermal agitation opposes this alignment. As temperature increases, thermal energy becomes more significant, disrupting the alignment and thus reducing the material's susceptibility to the magnetic field.

In the case of ferromagnets, above their Curie temperature (also known as the Curie point), they transition from a ferromagnetic state, where magnetic moments are spontaneously aligned, to a paramagnetic state. Above this temperature, the thermal fluctuations overcome the forces responsible for spontaneous alignment, and the material behaves according to Curie's Law, albeit with a different Curie constant compared to a purely paramagnetic substance. The Curie temperature itself is a critical point where the magnetic order changes.