Magnetodielectric Y-phase strontium hexagonal ferrite materials formed by sodium substitution

Patent metadata

Field	Value
Publication number	US-10049796-B2
Application number	US-201514887680-A
Country	US
Kind code	B2
Filing date	Oct 20, 2015
Priority date	Oct 24, 2014
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

Disclosed herein are embodiments of an enhanced resonant frequency hexagonal ferrite material and methods of manufacturing. The hexagonal ferrite material can be Y-phase strontium hexagonal ferrite material. In some embodiments, sodium can be added into the crystal structure of the hexagonal ferrite material in order to achieve high resonance frequencies while maintaining high permeability.

First claim

What is claimed is:

1. A magnetodielectric hexagonal ferrite comprising:
a Y-phase strontium hexagonal ferrite material having sodium substituted for strontium and including a trivalent or tetravalent ion to form a magnetodielectric hexagonal ferrite, the composition of the magnetodielectric hexagonal ferrite being Sr 2-x Na x Co 2-x M x Fe 12 O 22 when a trivalent ion is used, where M is a trivalent ion, and the composition of the magnetodielectric hexagonal ferrite being Sr 2-2x Na 2x Co 2x N x Fe 12 O 22 when a tetravalent ion is used, where N is a tetravalent ion, x being from 0<x≤ about 1.5 in the trivalent substitution and from 0<x≤ about 0.75 in the tetravalent substitution.

2. The hexagonal ferrite of claim 1 wherein M is selected from the group consisting of Al, Ga, Sc, Cr, Mn, In, Yb, Er, Y or other lanthanide.

3. The hexagonal ferrite of claim 1 wherein N is selected from the group consisting of Si, Ge, Ti, Zr, Sn, Ce, Pr, Hf, or Tb.

4. The hexagonal ferrite of claim 1 wherein a trivalent ion is used.

5. The hexagonal ferrite of claim 1 wherein a tetravalent ion is used.

6. The hexagonal ferrite of claim 1 wherein the magnetodielectric hexagonal ferrite has the composition Sr 1.75 Na 0.25 Co 1.75 M 0.25 Fe 12 O 22 .

7. The hexagonal ferrite of claim 1 wherein the magnetodielectric hexagonal ferrite has the composition Sr 1.5 Na 0.5 Co 1.5 M 0.5 Fe 12 O 22 .

8. The hexagonal ferrite of claim 1 wherein the loss factor of the magnetodielectric hexagonal ferrite remains below 4 at frequencies up to 1 GHz.

9. The hexagonal ferrite of claim 1 wherein the magnetodielectric hexagonal ferrite has a permeability of between around 5 and around 6 up to 1 GHz.

10. A method for improving magnetic properties of a hexagonal ferrite material, the method comprising:
substituting sodium into a Y-phase strontium hexagonal ferrite material for strontium; and
charge balancing either using a trivalent or tetravalent ion to form a magnetodielectric hexagonal ferrite, the composition of the magnetodielectric hexagonal ferrite being Sr 2-x Na x Co 2-x M x Fe 12 O 22 when a trivalent ion is used, where M is a trivalent ion, and the compositions of the magnetodielectric hexagonal ferrite being Sr 2-2x Na 2x Co 2x N x Fe 12 O 22 when a tetravalent ion is used, where N is a tetravalent ion, x being from 0<x≤about 1.5 in the trivalent substitution and from 0<x≤about 0.75 in the tetravalent substitution.

11. The method of claim 10 wherein the magnetodielectric hexagonal ferrite has the composition Sr 1.75 Na 0.25 Co 1.75 M 0.25 Fe 12 O 22 .

12. The method of claim 10 wherein the magnetodielectric hexagonal ferrite has the composition Sr 1.5 Na 0.5 Co 1.5 M 0.5 Fe 12 O 22 .

13. The method of claim 10 wherein the loss factor of the magnetodielectric hexagonal ferrite remains below 4 at frequencies up to 1 GHz.

14. The method of claim 10 wherein the magnetodielectric hexagonal ferrite has a permeability of between around 5 and around 6 up to 1 GHz.

15. A magnetodielectric antenna comprising:
a Y-phase strontium hexagonal ferrite material having sodium substituted for strontium and including a trivalent or tetravalent ion to form a magnetodielectric hexagonal ferrite, the composition of the magnetodielectric hexagonal ferrite being Sr 2-x Na x Co 2-x M x Fe 12 O 22 when a trivalent ion is used, where M is a trivalent ion, and the composition of the magnetodielectric hexagonal ferrite being Sr 2-2x Na 2x Co 2x N x Fe 12 O 22 when a tetravalent ion is used, where N is a tetravalent ion, x being from 0<x≤1.5 in the trivalent substitution and from 0<x≤about 0.75 in the tetravalent substitution.

16. The magnetodielectric antenna of claim 15 wherein the magnetodielectric hexagonal ferrite has the composition Sr 1.75 Na 0.25 Co 1.75 M 0.25 Fe 12 O 22 .

17. The magnetodielectric antenna of claim 15 wherein the magnetodielectric hexagonal ferrite has the composition Sr 1.5 Na 0.5 Co 1.5 M 0.5 Fe 12 O 22 .

18. The magnetodielectric antenna of claim 15 wherein the loss factor of the magnetodielectric hexagonal ferrite remains below 4 at frequencies up to 1 GHz.

19. The magnetodielectric antenna of claim 15 wherein the magnetodielectric hexagonal ferrite has a permeability of between around 5 and around 6 up to 1 GHz.

20. A radiofrequency device incorporating the hexagonal ferrite of claim 1 .

Assignees

• Skyworks Solutions Inc

Inventors

• Hill Michael David

Classifications

• C04B35/2683

  Other ferrites containing alkaline earth metals or lead · CPC title

• C04B35/26

  based on ferrites · CPC title

• C04B2235/3275

  Cobalt oxides, cobaltates or cobaltites or oxide forming salts thereof, e.g. bismuth cobaltate, zinc cobaltite · CPC title

• C04B2235/3286

  Gallium oxides, gallates, indium oxides, indates, thallium oxides, thallates or oxide forming salts thereof, e.g. zinc gallate · CPC title

• C04B2235/3293

  Tin oxides, stannates or oxide forming salts thereof, e.g. indium tin oxide [ITO] · CPC title