# Curie Constant

In physics, unlike other physical constants, the curie constant is a material dependent property. It expresses the relation between the magnetic susceptibility of a material to its temperature. Measured using K.A.T-1.m-1. In this article, let us know in detail about the Curie constant.

## Formula

In SI units the Curie constant can be expressed as

$$\begin{array}{l}C=\frac{\mu _{0}\mu _{B}^{2}}{3k_{B}}ng^{2}J(J+1)\end{array}$$

Where,

• C is the Curie constant.
• n is the number of magnetic atoms per unit volume.
• g is the g-factor.
• μB is the Bohr magneton.
• kB is the Boltzmann constant.
• J is the angular momentum quantum number.
• μ0 is the permeability of free space.

For the two-level system, the above equation can be reduced to

$$\begin{array}{l}C=\frac{1}{k_{B}}n\mu _{0}\mu ^{2}\end{array}$$

In Gaussian units, the Curie constant can be expressed as

$$\begin{array}{l}C=\frac{\mu _{B}^{2}}{3k_{B}}ng^{2}J(J+1)\end{array}$$

Where,

• C is the Curie constant.
• n is the number of magnetic atoms per unit volume.
• g is the g-factor.
• μB is the Bohr magneton.
• kB is the Boltzmann constant.
• J is the angular momentum quantum number.

For the two-level system, the above equation can be reduced to

$$\begin{array}{l}C=\frac{1}{k_{B}}n\mu ^{2}\end{array}$$

### Applications

The Curie constant is used in Curie law. Which states that for any magnetic field with a fixed value, the Magnetisation of the material is inversely proportional to the temperature. Mathematically given by-

$$\begin{array}{l}M=\frac{C}{T}B\end{array}$$

Where,

• M is the magnetisation of a material.
• B is the magnetic field.
• T is the temperature.
• C is the Curie constant.

Hope you have understood Curie’s constant. It is defined by its Units, the Formula in the SI system of Units and Gaussian units, and terms and their applications in physics, especially in Curie law.

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## Frequently Asked Questions – FAQs

### The Curie constant is represented using which alphabet?

The Curie constant is represented using the alphabet ‘C’.

### State Curie’s law

Curie’s law states that for any magnetic field with a fixed value, the material’s Magnetisation is inversely proportional to the temperature.

### Give the mathematical representation of Curie’s law?

$$\begin{array}{l}M=\frac{C}{T}B\end{array}$$

Where,
M is the magnetisation of a material.
B is the magnetic field.
T is the temperature.
C is the Curie constant.

### Define Boltzmann constant?

Boltzmann constant is the physical constant relating average kinetic energy of the gas particles and temperature of the gas represented by k or kB.

### How can Curie constant be expressed in Gaussian units?

In Gaussian units, the Curie constant can be expressed as:

$$\begin{array}{l}C=\frac{\mu _{B}^{2}}{3k_{B}}ng^{2}J(J+1)\end{array}$$

Where,
C is the Curie constant.
n is the number of magnetic atoms per unit volume.
g is the g-factor.
μB is the Bohr magneton.
kB is the Boltzmann constant.
J is the angular momentum quantum number.

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