Bismuth ruthenium M-type hexaferrite

1. A ferrite composition comprising a BiRuCo-M-type ferrite having the formula:

Me 1-x Bi x Co y Ru z Fe 12-t O 19

wherein Me is at least one of Sr, Pb, or Ba; x is 0.01 to 0.5; y is 0.1 to 2; z is 0 to 4, and t is 0 to 4;

wherein the Co is optionally at least partially replaced by at least one of Zn, Cu, or Mg by an amount of less than y,

wherein the Ru is optionally at least partially replaced by at least one of Ti, Sn, or Zr, where the substitution amount is not more than z.

2. The ferrite composition of claim 1 , wherein y is 1 to 2.

3. The ferrite composition of claim 1 , wherein Me is at least Ba.

4. The ferrite composition of claim 1 , wherein x is 0.01 to 0.5.

5. The ferrite composition of claim 1 , wherein the ferrite composition has at least one of a permeability of greater than or equal to 2.5 at a frequency of 1 to 2 gigahertz in the form of a solid ceramic; a permittivity of 8 to 12 at a frequency of 1 to 2 gigahertz in the form of a solid ceramic; a magnetic loss tangent tan N of less than or equal to 0.2 at a frequency of 1 to 2 gigahertz in the form of a solid ceramic; or wherein the ferrite composition has a dielectric loss tangent tank of less than or equal to 0.02 at a frequency of 1 to 2 gigahertz in the form of a solid ceramic.

6. The ferrite composition of claim 1 , wherein the Co is at least partially replaced by at least one of Zn, Cu, or Mg.

7. The ferrite composition of claim 1 , wherein the Ru is at least partially replaced by at least one of Ti, Sn, or Zr.

8. A composite comprising the ferrite composition of claim 1 and a polymer.

9. An article comprising the ferrite composition of claim 1 .

10. The article of claim 9 , wherein the article is an antenna, filter, inductor, circulator, or phase shifter.

11. The article of claim 9 , wherein the article is a microwave antenna.

12. The article of claim 9 , wherein the article is an antenna operable at a frequency of greater than or equal to 0.1 gigahertz.

13. A ferrite composition comprising a BiRuCo-M-type ferrite having the formula:

Ba 1-x Bi x Co y Ru z Fe 12-t O 19

wherein x is 0.01 to 0.5; y is 0.1 to 2; z is 0 to 4, and t is 0 to 4.

14. A method of making the ferrite composition, comprising:

mixing ferrite precursor compounds comprising Me, Fe, Bi, Co, and Ru; and

sintering the ferrite precursor compounds in an oxygen atmosphere to form a BiRuCo-M-type ferrite having the formula

Me 1-x Bi x Co y Ru z Fe 12-t O 19

wherein Me is at least one of Sr, Pb, or Ba; x is 0.01 to 0.5; y is 0.1 to 2; z is 0 to 4, and t is 0 to 4;

wherein the Co is optionally at least partially replaced by at least one of Zn, Cu, or Mg by an amount of less than y,

wherein the Ru is optionally at least partially replaced by at least one of Ti, Sn, or Zr, where the substitution amount is not more than z.

15. The method of claim 14 , wherein the ferrite precursor compounds comprise MeCO 3 , Bi 2 O 3 , Co 3 O 4 , RuO 2 , and Fe 2 O 3 .

16. The method of claim 15 , wherein the ferrite precursor compounds comprise 5 to 20 weight percent of MeCO 3 , 0.01 to 20 weight percent of Bi 2 O 3 , 1 to 15 weight percent of Co 3 O 4 , 0.1 to 10 weight percent of RuO 2 , and 50 to 80 weight percent of Fe 2 O 3 ; all based on the total weight of the precursor compounds.

17. The method of claim 14 , wherein the sintering occurs at a sintering temperature of 1,000 to 1,300° C. for a sintering time of 1 to 20 hours.

18. The method of claim 14 , further comprising calcining the ferrite precursor compounds in air prior to the sintering.

19. The method of claim 14 , further comprising mixing the ferrite precursor compounds with a binder prior to the sintering.

20. The method of claim 14 , further comprising forming the ferrite precursor compounds prior to the sintering.