NANO-MAGNETIC TECHNOLOGY

Soft magnetic cores are inductive components used in machineries to power electronic devices, such as cell phones, telecommunications, radars, computers, satellites, and automobiles. High frequency inductive components require magnetic cores with high resistivity, high permeability, low hysteresis loss and dielectric loss. Due to the low resistivity, metallic alloys cannot be used beyond 1 MHz. Ferrites have been extensively used as soft magnetic materials for five decades without major innovation despite significant power loss at elevated frequencies, which is the key factor limiting the miniaturization of electronics devices and equipment. Nanocompositing has opened a new opportunity to develop novel high frequency soft magnetic materials. In conventional micrometer sized magnetic materials, each particle possesses many magnetic domains (or multidomains) which cause interference or resonance. Domain wall resonance restricts the frequency characteristics of the initial permeability. When the size of the magnetic particle is smaller than the critical size for multidomain formation, the particle is in a single domain state. Domain wall resonance is avoided, and the material can work at higher frequencies.

Inframat® is developing metal/ceramic nanocomposites for the next generation of high frequency magnetic applications. Our proprietary process involves using a wet chemical synthesis route for fabricating Co/insulators, Ni-Fe/insulators, Ni ferrite/insulator nanomaterials. Key to Inframat's technology is the synthesis of nanocomposites using an aqueous solution reaction of metal and ceramic precursors. The result is a uniform mixing of the constituent elements at the molecular level. Low temperature annealing of the material facilitates the formation of a thin amorphous SiO2 insulating layer coated on the surfaces of magnetic particles. The material then has no overall electric conductivity, and the eddy current produced within the particle is extremely small at high frequency up to microwave and millimeter wave frequencies. By replacing commercially used ferrite cores with high performance magnetic nanocomposites, the inductive components could be made lighter, smaller, economical, and highly durable- contributing greatly to improved performance in high frequency devices, e.g., telecommunications.

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