Curie constant
In magnetism, 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 in kelvins (K),[1] by
- ,[2]
where is the number of magnetic atoms (or molecules) per unit volume, is the Landé g-factor, is the Bohr magneton, is the angular momentum quantum number and is Boltzmann's constant. For a two-level system with magnetic moment , the formula reduces to
- ,
while the corresponding expressions in Gaussian units are
- ,
- .
The constant is used in Curie's Law, which states that for a fixed value of an applied magnetic field , the magnetization of a material is (approximately) inversely proportional to temperature.
- .
This equation was first derived by Pierre Curie.
Because of the relationship between magnetic susceptibility , magnetization and applied magnetic field is almost linear at low fields, then
- ,
this shows that for a paramagnetic system of non-interacting magnetic moments, magnetization is inversely related to temperature .
See also
References
- Coey, J. M. D.; Coey, J. M. D. (2010-03-25). Magnetism and Magnetic Materials. Cambridge University Press. ISBN 978-0-521-81614-4.
- Kittel, Charles (11 November 2004). Introduction to Solid State Physics, 8th Edition. Wiley. pp. 304. ISBN 0-471-41526-X.