Curie's Law Calculator

Curie's law calculator helps you calculate the magnetization of paramagnetic materials, including their dependence on temperature. You can try the calculator right now or keep on reading to learn more about the magnetic susceptibility of paramagnetic materials and the Curie constant.

We can classify all the materials depending on their behavior in the presence of a magnetic field. A magnetic field attracts paramagnetic materials. The origin of this attractive force lies in the structure of paramagnets.

Inside the paramagnets, some atoms have electrons acting as tiny magnets. If we place an external magnet close to a paramagnetic material, these small magnets inside will flip just like blackboard magnets. In effect, they will be attracted to the external magnet, and the whole material will be pulled together with them.

OK, so we know that paramagnetic materials in the presence of a magnetic field become magnets. The natural question is: How strong are they? Curie's law answers this question.

We measure the strength of magnets using magnetization. Curie's law tells us that for not too strong magnetic fields and not too low temperatures (comparing with the absolute zero temperature, 0 K), the magnetization M is:

M = C/T × B,

where:

• C – Curie constant [K·A/(T·m)];
• T – Temperature [K]; and
• B – External magnetic field.

The factor C/T is the magnetic susceptibility, often denoted by χ. Curie's law states that magnetization depends on the Curie constant C and the temperature T. Why is that?

The structure of the material depends on the number of tiny atomic magnets and the strength of each of them. The larger the number of them, or the stronger they are, the larger the susceptibility. The Curie constant C carries this information. If you want to learn more about the Curie constant, check the Curie constant calculator.

The Curie constant is not the end of the story. The second factor is the temperature. Thermal fluctuations kick the atomic magnets. The larger the temperature, the larger the jitters and the more kicking. You can learn more about this phenomenon with the Gibbs factor calculator. Because of these fluctuations, the atomic magnets are not perfectly aligned. This effect decreases the magnetization M.

With the help of our calculator, you can quickly determine the magnetization for different situations. For example:

1. Choose a room temperature: T = 20 °Cz.
2. Fix the external field: B = 1 T.
3. Choose the Curie constant: C = 1.3 K·A/(T·m).
4. The magnetization is: M = 0.004435 A/m.