Magnetic terms
Curie temperature
If the Curie temperature is reached, the magnetic material loses its magnetism.
Operating temperature
The operating temperature is the highest temperature to which a magnet can be exposed without permanent magnetic loss. It is an approximate value, as it depends on the dimensioning. Factors such as mechanical or chemical stress can further limit the maximum operating temperature.
Energy product (W × H)max
The maximum energy product of the flux density B and the field strength H is the most important quality value of a magnetic material. The higher the energy product, the greater the magnetic energy. The greater the (B × H)max value of a magnetic material, the smaller the magnetic volume required for a specific task can be, all other things being equal.
Coercive field strength Hc
The coercive field strength is the field strength that must be applied to eliminate magnetization. The higher the value, the higher the resistance to magnetization. A distinction is made between HcB and HcJ.
Remanence (Br)
Remanence is the remaining magnetization in a magnetic material that has been magnetized to saturation in a closed circuit. The remanence is specified in Gauss (G), Tesla (T) or millitesla (mT).
| Magnetic material | Energy product | Remanence | Coercive field strength | Temperature coefficient | max. operating temperature | Curie temperature | Density | |
|---|---|---|---|---|---|---|---|---|
| (W×H)max kJ/m3 | Br mT | HcB kA/m | HcJ kA/m | per 1 °C | °C | °C | g/cm3 | |
| Barium ferrite isotropic | 7,2 - 7,6 | 210 - 220 | 130 - 135 | 220 | -0,2 % | 250 | 450 | 4,9 |
| Barium ferrite anisotropic | 28,9 - 29,5 | 390 - 400 | 145 - 160 | 150 - 165 | -0,2 % | 250 | 450 | 4,9 |
| Strontium ferrite anisotropic | 24,5 - 25,5 | 350 - 370 | 210 - 245 | 220 - 255 | -0,2 % | 250 | 450 | 4,9 |
| AINiCo 500 | 35 - 36 | 1120 - 1160 | 47 - 49 | 47 - 49 | -0,02 % | 400 | 890 | 7,3 |
| Samarium-Cobalt SmCo5 | 140 - 150 | 850 - 890 | 620 - 670 | 1100 - 120 | -0,04 % | 250 | 720 | 8,3 |
| Samarium-Cobalt Sm2Co17 | 190 - 205 | 1000 - 1050 | 680 - 750 | 1195 - 1500 | -0,03 % | 250 | 800 | 8,3 |
| Neodymium-iron-boron NdFeB N35* | 260 - 285 | 1180 - 1220 | 860 - 915 | > 955 | -0,13 % | 80 | 310 | 7,4 |
| Neodymium-iron-boron NdFeB N48* | 358 - 392 | 1370 - 1410 | 859 - 950 | > 955 | -0,13 % | 80 | 310 | 7,4 |
Values determined at 20 °C temperature. *Versions up to 220 °C operating temperature available.
