| Powdered iron | Ferromagnetic powder particles are insulated from one another and pressed into a core. The distributed gaps between particles reduce the need for a single large air gap. | Distributed-gap behavior supports energy storage and helps the inductor tolerate DC bias. Inductance still decreases as current and magnetic flux increase, depending on the core grade and design. | Often cost-effective; available in practical shapes such as toroids; can provide gradual inductance roll-off under increasing DC bias. | Core loss and temperature rise depend on frequency, flux swing, material grade, and waveform. It may require a larger core than a lower-loss material for some high-frequency designs. | DC-link chokes, boost and buck-boost stages, and other energy-storage or ripple-filtering positions where bias tolerance and cost matter. |
| Ferrite | A ceramic magnetic material, commonly used as a solid core; power-inductor designs may include a deliberate air gap to store energy. | Can offer low core loss at suitable switching frequencies. A gapped design stores energy, but the gap and core size must be chosen to meet DC-bias requirements. | Useful for high-frequency power conversion; broad range of material grades and core shapes. | Ferrite is comparatively brittle, and a gapped core can produce localized fringing fields and winding losses near the gap. | High-frequency inverter stages and compact converters when switching-frequency loss and component size are important. |
| Sendust (Fe-Si-Al) | An iron-silicon-aluminum powder core with distributed gaps formed by the insulated particles. | Distributed-gap construction supports energy storage and DC-bias operation. Performance varies with the selected grade and operating conditions. | Can offer a useful balance of core loss, bias performance, and core size in power-inductor applications. | Material cost and loss performance should be compared with alternatives at the actual switching frequency, flux swing, and temperature. | Energy-storage chokes and power-factor-correction or DC-DC stages where distributed-gap behavior is useful. |
| MPP (molypermalloy powder) | A distributed-gap powder core made from a nickel-iron-molybdenum alloy. | Designed for energy storage with stable inductance under DC bias; core loss and usable flux depend on the specific grade and design. | Can provide low core loss and good bias characteristics in demanding power-inductor applications. | Typically more expensive than many general-purpose powder-core options. | Compact, higher-performance energy-storage inductors where loss and inductance stability justify the material cost. |
| High-flux powder alloy | A distributed-gap powder core based primarily on an iron-nickel alloy. | Offers high saturation capability among common powder-core families, which can be helpful in high-current energy-storage designs. | Useful when high DC bias or high current is a major design constraint. | Usually costs more than standard powdered iron; core loss must be checked against the chosen grade and operating point. | High-current boost converters, DC-link chokes, and energy-storage stages requiring strong bias capability. |
| Nanocrystalline | A very thin-ribbon soft-magnetic alloy core, often formed as a wound or cut core; a gap may be added for energy storage. | Can provide high permeability and low loss in suitable applications. Energy-storage capability depends on the gap, core geometry, and DC-bias design. | Useful in designs seeking high magnetic performance and reduced losses over an appropriate frequency range. | Core handling, gap design, availability, and cost may be less straightforward than for common powdered-iron cores. | Selected high-performance inverter filters and power stages, subject to frequency, bias, and mechanical requirements. |