Curie constant

The Curie constant is a material-dependent property that relates a material's magnetic susceptibility to its temperature.

The Curie constant, when expressed in SI units, is given by

C={\frac {\mu _{0}\mu _{B}^{2}}{3k_{B}}}Ng^{2}J(J+1)

^[1]

where $N$ is the number of magnetic atoms (or molecules) per unit volume, $g$ is the Landé g-factor, $\mu _{B}$ (9.27400915e-24 J/T or A·m²) is the Bohr magneton, $J$ is the angular momentum quantum number and $k_{B}$ is Boltzmann's constant. For a two-level system with magnetic moment $\mu$ , the formula reduces to

C={\frac {1}{k_{B}}}N\mu _{0}\mu ^{2}

The constant is used in Curie's Law, which states that for a fixed value of a magnetic field, the magnetization of a material is (approximately) inversely proportional to temperature.

{\mathbf {M}}={\frac {C}{T}}{\mathbf {B}}

This equation was first derived by Pierre Curie.

Because of the relationship between magnetic susceptibility $\chi$ , magnetization $\scriptstyle \mathbf {M}$ and applied magnetic field $\scriptstyle {\mathbf {H}}$ :

\chi ={\frac {{\mathbf {M}}}{{\mathbf {H}}}}

this shows that for a paramagnetic system of non-interacting magnetic moments, magnetization $\scriptstyle \mathbf {M}$ is inversely related to temperature $T$ (see Curie's Law).

References

↑ Kittel, Charles. Introduction to Solid State Physics, 8th Edition. Wiley. p. 304. ISBN 0-471-41526-X.

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Curie constant

See also

References