Nanocrystalline Soft Magnetic Material FINEMET®


Proterial developed the first nanocrystalline soft magnetic material in the world, named “FINEMET®”. FINEMET® has high saturation flux density and high permeability. It also has stable temperature characteristics. FINEMET® provides excellent performance in electromagnetic noise suppression and contributes to energy saving. It will allow reduction in size and weight of electric and electronics devices as well. It is our hope, “FINEMET®” will be the best solution for your application due to its unique soft magnetic properties.

We propose a method to use materials tailored to your company.

What is FINEMET® ?

FINEMET® is crystalized alloy ribbon with main chemical composition of Fe.
This crystalized alloy have grains which are extremely uniform and small “about 10nm in size”.
FINEMET® is Proterial's original product realizes drastic improvement of magnetic characteristics.

Various product groups


1) Satisfy both high saturation magnetic flux density and high permeability (High permeability, High saturation flux density)

High saturation magnetic flux density comparable to Fe-based amorphous metal. High permeability comparable to Co-based amorphous metal.

2) Low core loss (Low core loss)

1/5th the core loss of Fe based amorphous metal and approximately the same core loss as Co-based amorphous metal.

3) Excellent temperature characteristics and small aging effects (Excellent temperature characteristics)

Small permeability variation (less than ±10%) at a temperature range of -50°C~150°C. Unlike Co-based amorphous metals, aging effects are very small.

4) Low magnetostriction (Low magnetstriction)

Less affected by mechanical stress. Very low audio noise emission.

5) Excellent characteristics over wide frequency range (High squareness)

High permeability and low core loss over wide frequency range, which is equivalent to Co-based amorphous metal.

6) Flexibility to control magnetic properties“B-H curve shape”during annealing (High permeability)

Three types of B-H curve squareness, high, middle and low remanence ratio, corresponding to various applications.


High saturated flux density, high relative permeability and low core loss. Superior to conventional materials.


Features and Typical Applications of FINEMET®

Proterial, Ltd. produces various types of soft magnetic materials, such as Permalloy, soft ferrite, amorphous metal, and FINEMET®, and we use these materials in our product's applications. We continually improve our material technology and develop new applications by taking advantage of the unique characteristics these materials provide. FINEMET® is a good example. It is our hope, FINEMET® will be the best solution for your application.

Features and Typical Applications of FINEMET® Common mode chokess Magnetic shielding sheets FM SHIELD® Shield Yoke Sheet for Wireless Chargers Pulsed power cores Surge absorbers Low Core Loss Noncut Core Low Core Loss Cut Cores

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