Mo-doped Co2Z-type ferrite composite material for use ultra-high frequency antennas
AssigneeRogers Corporation
InventorsYajie Chen, Vincent Harris
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Abstract
A Co2Z hexaferrite composition is provided containing molybdenum and one or both of barium and strontium, having the formula (Ba2Sr(3-Z)Co(2+X))MoxFe(y-2x)O41 where x=0.01 to 0.20; y=20 to 24; and z=0 to 3. The composition can exhibit high permeabilities and equal or substantially equal values of permeability and permittivity while retaining low magnetic and dielectric loss tangents and loss factors. The composition is suitable for high frequency applications such as ultrahigh frequency and microwave antennas and other devices.
Claims52
A hexaferrite composition comprising iron, cobalt, one or both of barium and strontium, and molybdenum, wherein said ferrite composition comprises a Z-type hexaferrite phase, having the formula
- (BazSr(3-z))Co(2+x)MoxFe(y-2x)O41
- where x=0.01 to 0.20;
- y=20 to 24;
- and
- z=0 to 3.
A method of making a hexaferrite composition comprising:
- (a) providing hexaferrite phase precursor compounds comprising Fe, Ba, Co, and Mo,
- (b) calcining the hexaferrite phase precursor compounds in air to form a material comprising a Z-type hexaferrite phase.
A method of making a hexaferrite composition comprising:
- (a) providing hexaferrite phase precursor compounds comprising more than 0 to 0.96 wt. % MoO2, 22.10 to 22.18 wt. % BaCO3, 6.02 to 6.59 wt. % Co3O4, and 70.35 to 71.8 wt. % Fe2O3,
- (b) calcining the hexaferrite phase precursor compounds at 1000 to 1300° C. in air to form a material comprising a Z-type hexaferrite phase;
- (c) crushing the material formed in step (b) to form a powder mixture, forming the powder mixture and a binder into a compact, and
- (d) sintering the compact at 1200 to 1280° C. for 4 to 20 hours in an oxygen atmosphere.
- (e) crushing the material formed in step (d) to form a second powder mixture;
- and
- (f) annealing the second powder mixture formed in step (e) at 800 to 1000° C. for 9 to 20 hours.
Dependencies are inferred from the claim text.