Composite hexagonal ferrite materials
Disclosed herein are embodiments of composite hexagonal ferrite materials formed from a combination of Y phase and Z phase hexagonal ferrite materials. Advantageously, embodiments of the material can have a high resonant frequency as well as a high permeability. In some embodiments, the materials can be useful for magnetodielectric antennas.
1. A composite hexagonal ferrite material, the material comprising:
a base y-phase hexagonal ferrite composition; and
a doped-in z phase hexagonal ferrite material having a formula Sr 3-x-y Ba x Na y Co 2-y Sc y Fe 24 O 41 , 0<x<3, 0<y<1.5, forming a composite hexagonal ferrite material having a Q value of greater than 15 at 1 GHz.
2. The composite hexagonal ferrite material of claim 1 wherein the composite hexagonal ferrite material includes two phases.
3. The composite hexagonal ferrite material of claim 1 wherein the composite hexagonal ferrite material has a Q value of greater than 20 at 1 GHz.
4. The composite hexagonal ferrite material of claim 1 wherein the composite hexagonal ferrite material has a real permeability of between 3 and 7 at 1 GHz.
5. The composite hexagonal ferrite material of claim 1 wherein the composite hexagonal ferrite material has a real permeability of greater than 6 at 1 GHz.
6. The composite hexagonal ferrite material of claim 1 wherein the composite hexagonal ferrite material has an imaginary permeability of less than 1 at 1 GHz.
7. The composite hexagonal ferrite material of claim 1 wherein the composite hexagonal ferrite material has a quality factor of greater than 15 at 1 GHz.
8. The composite hexagonal ferrite material of claim 1 wherein the y-phase hexagonal ferrite composition includes Sr 1.6 Na 0.4 Sc 0.4 Co 1.6 Fe 12 O 22 .
9. A method of forming a composite hexagonal ferrite material, the method comprising combining a y-phase hexagonal composition at least partially with a z phase hexagonal ferrite material having a formula Sr 3-x-y Ba x Na y Co 2-y Sc y Fe 24 O 41 , 0<x<3, 0<y<1.5, thereby forming a composite hexagonal ferrite material having a Q value of greater than 15 at 1 GHz.
10. The method of claim 9 further including doping the composite hexagonal ferrite material with indium or zirconium to reduce strontium.
11. The method of claim 9 wherein the composite hexagonal ferrite material has a Q value of greater than about 20 at 1 GHz.
12. The method of claim 9 wherein the composite hexagonal ferrite material has a real permeability of between 3 and 7 at 1 GHz.
13. The method of claim 9 wherein the y-phase hexagonal ferrite composition includes Sr 1.6 Na 0.4 Sc 0.4 Co 1.6 Fe 12 O 22 .
14. An antenna formed from a composite hexagonal ferrite material, the antenna comprising:
a base y-phase hexagonal ferrite composition; and
a doped-in z phase hexagonal ferrite material having a formula Sr 3-x-y Ba x Na y Co 2-y Sc y Fe 24 O 41 , 0<x<3, 0<y<1.5, forming a composite hexagonal ferrite material having a Q value of greater than 15 at 1 GHz.
15. The antenna of claim 14 wherein the antenna is part of a wireless device.
16. The antenna of claim 14 wherein the antenna is part of a tablet.
17. The antenna of claim 14 wherein the antenna is usable at frequencies of 1 GHz and above.
18. The antenna of claim 14 wherein the composite hexagonal ferrite material has a Q value of greater than about 20 at 1 GHz.
19. The antenna of claim 14 wherein the composite hexagonal ferrite material has a real permeability of between 3 and 7 at 1 GHz.
20. The antenna of claim 14 wherein the y-phase hexagonal ferrite composition includes Sr 1.6 Na 0.4 Sc 0.4 Co 1.6 Fe 12 O 22 .