The Curie constant sets how strongly a paramagnet magnetises at a given temperature. It depends on how many magnetic ions there are per volume and the size of their moments.
How to use the Curie Constant Calculator
- Number density from
- Number density (m⁻³)
- Lattice constant a
- Atoms per cubic cell
- Effective moment (Bohr magnetons)
Results update as you type, every field has its own unit menu, and everything is calculated in your browser.
How it works
Choose how to give the number density and enter the effective magnetic moment.
Inputs explained
| Field | What to enter |
|---|---|
| Number density from | Choose one: Direct value, Cubic lattice |
| Number density (m⁻³) | A number |
| Lattice constant a | Units: Å, nm, pm |
| Atoms per cubic cell | Choose one: Simple cubic (1), Body-centred (2), Face-centred (4) |
| Effective moment (Bohr magnetons) | A number |
Example values
How the main result changes when Number density changes and everything else stays at the example values above:
| Number density (m⁻³) | Curie constant C (K) |
|---|---|
| 5.00e27 | 1.4289 |
| 7.50e27 | 1.4289 |
| 1.00e28 | 1.4289 |
| 1.25e28 | 1.4289 |
| 1.50e28 | 1.4289 |
| 2.00e28 | 1.4289 |
Formula
C = μ₀·n·μ² / (3·k_B), μ = p·μ_B, n = atoms per cell / a³
Worked example
Inputs — Number density from: Cubic lattice; Lattice constant a: 4 Å; Atoms per cubic cell: Simple cubic (1); Effective moment (Bohr magnetons): 5.92.
Results — Number density = 1.5625e28 m⁻³; Curie constant C = 1.42891 K.
Key terms
- Bohr magneton
- eħ/(2mₑ).
Frequently asked questions
What is the effective moment of Mn²⁺?
About 5.92 μ_B.
What units does C have here?
Kelvin (dimensionless susceptibility × K).
How is C used?
χ = C/T (Curie law).
What is a Bohr magneton?
The natural unit of electron magnetic moment, 9.274 × 10⁻²⁴ J/T.