Soft Magnetic Materials, Permeability & Core Loss Reference Sheet
This technical reference sheet details the physical parameters, operational limits, and Steinmetz core-loss coefficients across soft magnetic material classes. Cross-reference specific terminology in our electromagnetic coil design and winding glossary.
Soft Magnetic Material Characteristics Matrix
| Material Class | Initial Permeability ($\mu_i$) | Saturation Flux Density ($B_{\text{sat}}$) | Curie Temp ($T_c$) | Primary Application / Key Advantage |
|---|---|---|---|---|
| MnZn Ferrites | 1,000 – 15,000 | 350 – 530 mT | > 200 °C | High-frequency transformers & inductors (10 kHz – 2 MHz). Learn more in the glossary under Ferrites. |
| NiZn Ferrites | 100 – 1,500 | 250 – 400 mT | > 150 °C | High-frequency RF & EMI suppression (> 10 MHz) due to extremely high resistivity ($\rho$). |
| Sendust (Kool Mμ) | 26 – 125 | ~ 1,050 mT | > 500 °C | Power factor correction (PFC) chokes with soft-saturation behavior. See Sendust in the glossary. |
| Nanocrystalline | 20,000 – 100,000 | 1,200 – 1,300 mT | > 560 °C | Ultra-compact common-mode chokes and wideband transformers. Details in Nanocrystalline cores. |
| Mu-Metals (Ni-Fe) | 80,000 – 200,000 | 700 – 800 mT | ~ 400 °C | Precision magnetic shielding and low-frequency sensor cores. Cross-link: Mu-metals entry. |
| Amorphous Metals | 2,000 – 10,000 | 1,500 – 1,860 mT | > 350 °C | High-efficiency grid power conversion and pulsed-power systems. See Amorphous metals. |
Steinmetz Core Loss Coefficients ($P_v = k \cdot f^\alpha \cdot B^\beta$)
Volumetric core loss ($P_v$, in $\text{kW/m}^3$) under sinusoidal excitation. Review mathematical foundations in our Steinmetz equation glossary term or explore operational strategies in our guide on preventing core saturation in high-current inductor design.
| Material Grade | Frequency Range ($f$) | Coefficient $k$ | Exponent $\alpha$ (Freq) | Exponent $\beta$ (Flux) |
|---|---|---|---|---|
| N87 (MnZn Ferrite) | 25 – 100 kHz | 7.13 | 1.42 | 2.62 |
| N97 (MnZn Ferrite) | 50 – 200 kHz | 4.82 | 1.51 | 2.71 |
| 3C95 (MnZn Ferrite) | 20 – 150 kHz | 5.20 | 1.46 | 2.55 |
For further material processing rules, refer to our comprehensive guide on soft magnetic materials processing.