IP Library Granted Patent US 8,354,037
Granted Patent B2
US 8,354,037 · App. 12/406,575 · Granted Jan 15, 2013

High-frequency magnetic material and method of manufacturing the same

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Quick Facts
Patent No.
US 8,354,037
App. No.
12/406,575
Granted
Jan 15, 2013
Kind
B2
Abstract

To provide a high-frequency magnetic material having a superior radio wave absorption property in a high frequency region and a method of manufacturing the same. The high-frequency magnetic material and the method of manufacturing the same includes a magnetic substance containing metal nanoparticles, the metal nanoparticles are magnetic metals containing at least one kind of Fe, Co, and Ni, an average particle diameter of the metal nanoparticles is equal to or less than 200 nm, first clusters having network-like structures with continuous metal nanoparticles and the average diameter equal to or less than 10 μm are formed, second clusters having network-like structures with the continuous first clusters and the average diameter equal to or less than 100 μm are formed, and the entire magnetic substance has a network-like structure with the continuous second clusters.

Claims (18)

1. A high-frequency magnetic material comprising a magnetic substance containing metal nanoparticles,

wherein the metal nanoparticles are magnetic metals containing at least one kind of Fe, Co, and Ni,

an average particle diameter of the metal nanoparticles is equal to or less than 200 nm,

within the magnetic substance, first clusters having network-like structures with continuous metal nanoparticles and the average diameter equal to or less than 10 μm are formed, within the magnetic substance, second clusters having network-like structures with the continuous first clusters and the average diameter equal to or less than 100 μm are formed,

the magnetic substance has a network-like structure with the continuous second clusters, and

surface of the metal nanoparticles are partially coated with oxide.

2. The material according to claim 1 , wherein spaces between the metal nanoparticles are filled with dielectrics.

3. The material according to claim 1 , wherein the metal nanoparticles contain non-magnetic metals, and

the oxide contains at least one kind of non-magnetic metal of the non-magnetic metals.

4. The material according to claim 1 , wherein the metal nanoparticles contain at least one of C (carbon) and N (nitrogen).

5. The material according to claim 1 , wherein magnetic anisotropy of the metal nanoparticles is equal to or more than 23.9×10 3 A/m.

6. The material according to claim 1 , wherein resistivity of the magnetic substance is from 1 mΩ·cm to 100 kΩ·cm, and a real component μ′ of complex magnetic permeability of the magnetic substance is equal to or more than three at 1 GHz.

7. A high-frequency magnetic material comprising a magnetic substance containing metal nanoparticles,

wherein the metal nanoparticles are magnetic metals containing at least one kind of Fe, Co, and Ni,

an average particle diameter of the metal nanoparticles is equal to or less than 200 nm,

within the magnetic substance, first clusters having network-like structures with continuous metal nanoparticles and the average diameter equal to or less than 10 μm are formed, within the magnetic substance, second clusters having network-like structures with the continuous first clusters and the average diameter equal to or less than 100 μm are formed,

the magnetic substance has a network-like structure with the continuous second clusters, and

spaces between the metal nanoparticles are filled with dielectrics, surface of the metal nanoparticles are partially coated with oxide, the metal nanoparticles contain non-magnetic metals, the oxide contains at least one kind of non-magnetic metal of the non-magnetic metals, and the metal nanoparticles contain at least one of C (carbon) and N (nitrogen).

Assignments (2)
NUNC PRO TUNC ASSIGNMENT Recorded Apr 1, 2026
From: KABUSHIKI KAISHA TOSHIBA
To: KABUSHIKI KAISHA TOSHIBA; NITERRA MATERIALS CO., LTD.
Reel/Frame 074240/0867 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 19, 2009
From: HARADA, KOUICHI; SUETSUNA, TOMOHIRO; SUENAGA, SEIICHI
To: KABUSHIKI KAISHA TOSHIBA
Reel/Frame 022421/0787 →