Paramagnets become magnetised in a field, but thermal motion fights the alignment. Pierre Curie found that the magnetisation is inversely proportional to temperature – the basis of magnetic thermometers at very low temperatures.
How to use the Curie’s Law Calculator
- Curie constant C (K·A/(T·m))
- Magnetic field B
- Temperature T
Results update as you type, every field has its own unit menu, and everything is calculated in your browser.
How it works
Enter the Curie constant, magnetic field and temperature.
Tips
- Use absolute temperature (K) in gas laws and efficiency formulas.
- Temperature differences are the same in K and °C.
- Heat = mass × specific heat × temperature change when no phase change occurs.
- Phase changes need latent heat at a constant temperature.
Common mistakes to avoid
- Using °C in pV = nRT.
- Forgetting latent heat during melting or boiling.
- Confusing heat capacity (J/K) with specific heat (J/(kg·K)).
Inputs explained
| Field | What to enter |
|---|---|
| Curie constant C (K·A/(T·m)) | A number |
| Magnetic field B | Units: T, mT, µT, G, nT |
| Temperature T | Units: K, °C, °F |
What each result means
- Magnetisation M = [Curie constant C (K·A÷(T·m))]×[Magnetic field B]÷[Temperature T]
- Magnetic susceptibility χ = 1.25663706212e-6×[Curie constant C (K·A÷(T·m))]÷[Temperature T]
Example values
How the main result changes when Curie constant C changes and everything else stays at the example values above:
| Curie constant C (K·A/(T·m)) | Magnetisation M (A/m) |
|---|---|
| 0.5 | 0.125 |
| 0.75 | 0.1875 |
| 1 | 0.25 |
| 1.25 | 0.3125 |
| 1.5 | 0.375 |
| 2 | 0.5 |
Formula
M = C·B/T, χ = μ₀·C/TWorked example
Inputs — Curie constant C (K·A/(T·m)): 1; Magnetic field B: 1 T; Temperature T: 4 K.
Results — Magnetisation M = 0.25 A/m; Magnetic susceptibility χ = 3.1416e-7.
Key terms
- Paramagnetism
- Weak attraction to magnetic fields from unpaired spins.
Frequently asked questions
When does Curie's law hold?
For paramagnets at high temperatures and weak fields.
What happens at low temperature and strong field?
Magnetisation saturates.
What is the Curie–Weiss law?
A modification for materials that order magnetically.
Where is it used?
Low-temperature thermometry and magnetic cooling.
What formula does the Curie's Law Calculator use?
M = C·B/T, χ = μ₀·C/T.