Ferrite vs Neodymium magnet
Ferrite and Neodymium magnet are genuine alternatives to one another — a choice somebody actually makes — and differ on 1 measured property, density most clearly.
Ferrite vs Neodymium magnet
These are different kinds of thing (material, alloy). Fewer properties mean the same thing across both, so a like-for-like reading may not be available.
Ferrite
A magnetic ceramic that barely conducts — which is why it works at frequencies no metal can, and why most of the magnets in the world are made of it.
Neodymium magnet
Neodymium, iron and boron in a structure that holds a magnetic field better than anything else known — and the reason a hard drive, an earbud and an electric motor can be small.
| Property | Ferrite | Neodymium magnet |
|---|---|---|
| Crystal system Only one of the two has a figure we can stand behind, so there is nothing to compare. | cubic | Not known |
| Density | 4.8–5.1 g/cm³ | 7.4–7.6 g/cm³ higher |
| Electrical conductivity Only one of the two has a figure we can stand behind, so there is nothing to compare. | 1e-7–0.001 MS/m | Not known |
| Melting point Only one of the two has a figure we can stand behind, so there is nothing to compare. | Not known | 1180 °C |
| Mohs hardness Only one of the two has a figure we can stand behind, so there is nothing to compare. | 5–6 | Not known |
Choosing between them
Ferrite is recorded as a substitute for Neodymium magnet — cheaper, less supply-constrained, better at temperature.
What it gives up: About a tenth the field strength per unit volume, so the magnet and everything built around it has to be bigger — which is disqualifying anywhere mass or size is the constraint.
In this application, on the evidence cited above.