Fundamental Material Properties
Core Composition: Formed by high-temperature sintering of iron oxide (Fe₂O₃) with metal oxides such as manganese, zinc, and nickel; classified as a composite oxide magnetic material.
High Resistivity:Resistivity ranges from 10² to 10⁸ Ω·m-far higher than that of metallic magnetic materials-enabling significant suppression of eddy current losses and suitability for high-frequency applications.
Magnetic Domain Magnetization Mechanism: The crystal lattice structure of internal magnetic ions forms ordered magnetic domains; under an external magnetic field, domain walls shift and domains realign, generating macroscopic magnetization.
Core Electromagnetic Operating Mechanisms
Complex Permeability: Permeability is expressed as a complex number (μ = μ' - jμ"); the real part (μ') represents magnetic field energy storage capacity, while the imaginary part (μ") characterizes electromagnetic energy loss.
High-Frequency Energy Loss Mechanism: In an alternating high-frequency magnetic field, internal magnetic domains undergo rapid flipping and friction, converting high-frequency electromagnetic wave energy into dissipated heat; typical values for μ" are around 50–200 (at 100 MHz).
Frequency Response Characteristics: Initial permeability ranges from 100 to 5,000 within the 1 MHz–1 GHz range; permeability gradually decreases as frequency rises, consistent with Snoek's limit.
