Core-shell type magnetic particle and high-frequency magnetic material
View Patent ↗A core-shell type magnetic particle comprises magnetic metal particle and an oxide coating layer formed on the surface of the magnetic metal particle. The magnetic metal particle contains a magnetic metal containing at least one selected from the group consisting of Fe, Co and Ni, a nonmagnetic metal and at least one element selected from carbon and nitrogen. The oxide coating layer is constituted of an oxide or a composite oxide containing the nonmagnetic metal which is one of the constituents of the magnetic metal particle.
1. A magnetic particle comprising:
a magnetic metal particle including a magnetic metal selected from the group consisting of Fe, Co and Ni, a nonmagnetic metal and at least one element selected from carbon and nitrogen, the element forming a solid solution with the magnetic metal, wherein the magnetic metal particle is a single crystal or a polycrystal; and
an oxide coating layer formed on a surface of the magnetic metal particle and being made of an oxide or a composite oxide, wherein the oxide or the composite oxide each contain the nonmagnetic metal which is one of the constituents of the magnetic metal particle.
2. The magnetic particle according to claim 1 , wherein the nonmagnetic metal is at least one metal selected from the group consisting of Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, rare earth elements, Ba and Sr.
3. The magnetic particle according to claim 1 , wherein the nonmagnetic metal and the element are each in an amount of 20 atom % or less in the magnetic metal particle.
4. The magnetic particle according to claim 1 , wherein the magnetic metal particle has an average diameter of 1 nm or more and 1000 nm or less.
5. The magnetic particle according to claim 1 , wherein the magnetic metal particle has an aspect ratio of 10 or more.
6. The magnetic particle according to claim 1 , wherein the oxide coating layer has a thickness of 0.1 nm or more and 100 nm or less.
7. A high-frequency magnetic material containing the magnetic particle according to claim 1 .
8. A high-frequency magnetic material comprising:
a plurality of magnetic material layers containing the magnetic particle according to claim 1 and each layer having a thickness of 1 μm or less; and
a plurality of nonmagnetic insulating oxide layers, each layer having a thickness of 1 μm or less,
wherein the magnetic material layers and the nonmagnetic insulating oxide layers are alternately laminated.
9. The high-frequency magnetic material according to claim 8 , wherein the nonmagnetic insulating oxide is an oxide of at least one metal selected from the group consisting of Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, rare earth elements, Ba and Sr.
10. The high-frequency magnetic material according to claim 9 , wherein the nonmagnetic insulating oxide is made of an oxide or a composite oxide containing at least one nonmagnetic metal which is the constituent of the oxide coating layer of the magnetic particle in magnetic material layer.