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

where
is the permeability constant,
is the number of magnetic atoms (or molecules) per unit volume,
is the Landé g-factor
,
(9.27400915e-24 J/T or A·m2) 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

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.

This equation was first derived by Pierre Curie
(Marie Curie's husband).
Because of the relationship between magnetic susceptibility
, magnetization
and applied magnetic field
:

this shows that for a paramagnetic system of non-interacting magnetic moments, magnetization
is inversely related to temperature
(see Curie's Law
).
Magnetic susceptibility
In electromagnetism, the magnetic susceptibility \chi_m is a dimensionless proportionality constant that indicates the degree of magnetization of a material in response to an applied magnetic field...
to its temperature.
Curie's constant in SI units is

where



Landé g-factor
In physics, the Landé g-factor is a particular example of a g-factor, namely for an electron with both spin and orbital angular momenta. It is named after Alfred Landé, who first described it in 1921....
,


Angular momentum
In physics, angular momentum, moment of momentum, or rotational momentum is a conserved vector quantity that can be used to describe the overall state of a physical system...
quantum number and



The constant is used in Curie's Law
Curie's law
In a paramagnetic material the magnetization of the material is directly proportional to an applied magnetic field. However, if the material is heated, this proportionality is reduced: for a fixed value of the field, the magnetization is inversely proportional to temperature...
, which states that for a fixed value of a magnetic field, the magnetization of a material is (approximately) inversely proportional to temperature.

This equation was first derived by Pierre Curie
Pierre Curie
Pierre Curie was a French physicist, a pioneer in crystallography, magnetism, piezoelectricity and radioactivity, and Nobel laureate. He was the son of Dr. Eugène Curie and Sophie-Claire Depouilly Curie ...
(Marie Curie's husband).
Because of the relationship between magnetic susceptibility
Magnetic susceptibility
In electromagnetism, the magnetic susceptibility \chi_m is a dimensionless proportionality constant that indicates the degree of magnetization of a material in response to an applied magnetic field...




this shows that for a paramagnetic system of non-interacting magnetic moments, magnetization


Curie's law
In a paramagnetic material the magnetization of the material is directly proportional to an applied magnetic field. However, if the material is heated, this proportionality is reduced: for a fixed value of the field, the magnetization is inversely proportional to temperature...
).