M-type hexaferrite having a planar anisotropy
AssigneeRogers Corporation
InventorsYajie Chen, Yu Wang
Life of this patent
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Abstract
In an aspect, an M-type ferrite comprises an element Me comprising at least one of Ba, Sr, or Pb; an element Me′ comprising at least one of Ti, Zr, Ru, or Ir; and an element Me″ comprising at least one of In or Sc. In another aspect, a method of making the M-type ferrite can comprise milling ferrite precursor compounds comprising oxides of at least Co, Fe, Me, Me′, and Me″ to form an oxide mixture; wherein Me comprises at least one of Ba, Sr, or Pb; Me′ is at least one of Ti, Zr, Ru, or Ir; and Me″ is at least one of In or Sc; and calcining the oxide mixture in an oxygen or air atmosphere to form the ferrite.
Claims22
A ferrite, wherein the ferrite comprises:
- an element Me comprising at least one of Ba, Sr, or Pb;
- an element Me′ comprising at least one of Ti, Zr, Ru, or Ir;
- and
- an element Me″ comprising at least one of In or Sc;
- and
- wherein the ferrite is an M-type ferrite, and
- wherein the ferrite has
- an average grain size is of 1 to 100 micrometers, as measured using transmission electron microscopy or field emission scanning electron microscopy,
- a permeability of greater than or equal to 37.5 at a frequency of 200 megahertz,
- a figure of merit of greater than or equal to 50 at a frequency of 200 megahertz,
- a magnetic loss tangent tan δμ of less than or equal to 0.8 at a frequency of 200 megahertz,
- a Snoek product of greater than or equal to 12 gigahertz over the frequency range of 1 to 300 megahertz, or
- a combination thereof.
A dual-phase ferrite, wherein the dual-phase ferrite comprises:
- a c-plane magnetic structure having a c-plane magnetocrystalline anisotropy and having the formula Me(CoMe′)xFe12-2xO19, wherein Me is at least one of Ba, Sr, or Pb;
- Me′ is at least one of Ti, Zr, Ru, or Ir;
- and x is 0.8 to 1.3;
- and
- a uniaxial magnetic structure having a uniaxial magnetocrystalline anisotropy and having the formula Me(Me″)yFe12-yO19, wherein Me is defined above;
- Me″ is at least one of In or Sc;
- and y is 0.01 to 12.
A composite comprising:
- a polymer comprising at least one of a fluoropolymer or a polyolefin;
- and
- a ferrite comprising
- an element Me comprising at least one of Ba, Sr, or Pb;
- an element Me′ comprising at least one of Ti, Zr, Ru, or Ir;
- and
- an element Me″ comprising at least one of In or Sc,
- wherein the ferrite is an M-type ferrite.
Dependencies are inferred from the claim text.