Granted Patent B2

US 12,424,362 · App. 17/923,127 · Granted Sep 23, 2025

Inventors: Yajie Chen (Burlington, MA); Yu Wang (Malden, MA)

Assignee: ROGERS CORPORATION

H01F1/348C01G49/009C04B35/2633C04B35/6261C04B35/62645C04B41/0072H01F1/10H01F1/113C04B2235/3213C04B2235/3215C04B2235/3224C04B2235/3232C04B2235/3244C04B2235/3275C04B2235/3286C04B2235/3296C04B2235/767C04B2235/786

Abstract

Claims (49)

1. 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 δ μ 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.

2. The ferrite of claim 1 , wherein the ferrite is in the form of a solid-solution.

3. The ferrite of claim 1 , 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.

4. The ferrite of claim 1 , wherein the ferrite has a permeability of greater than or equal to 37.5 at a frequency of 200 megahertz.

5. The ferrite of claim 1 , wherein the ferrite has a figure of merit of greater than or equal to 50 at a frequency of 200 megahertz.

6. The ferrite of claim 1 , wherein the ferrite has a magnetic loss tangent tan δ μ of less than or equal to 0.8 at a frequency of 200 megahertz.

7. The ferrite of claim 1 , wherein the ferrite has a Snoek product of greater than or equal to 12 gigahertz over the frequency range of 1 to 300 megahertz.

8. 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′) x Fe 12-2x O 19 , 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″) y Fe 12-y O 19 , wherein Me is defined above; Me″ is at least one of In or Sc; and y is 0.01 to 12.

9. The dual-phase ferrite of claim 8 ,

wherein the dual-phase ferrite has the formula (Me(CoMe′) x Fe 12-2x O 19 ) (MeMe″ y Fe 12-y O 19 ), wherein x is 0.8 to 1.3, y is 0.01 to 12, and z is 0.005 to 2.

10. The dual-phase ferrite of claim 8 , wherein the c-plane magnetic structure has the formula of Ba(CoTi) x Fe 12-2x O 19 , wherein x is 0.8 to 1.3.

11. The dual-phase ferrite of claim 8 , wherein the uniaxial magnetic structure has the formula Ba(In) y Fe 12-y O 19 , wherein y is 0.01 to 6.

12. The dual-phase ferrite of claim 8 , wherein a mole ratio of the c-plane magnetic structure to the uniaxial magnetic structure is 1:0.005 to 1:2.

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

14. 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.

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

16. The article of claim 15 , wherein the article is an antenna, a filter, an inductor, a circulator, or an EMI suppressor.

17. A method of making the dual-phase ferrite of claim 8 , the method comprising:

milling ferrite precursor compounds comprising oxides of at least Co, Fe, Me, Me′, and Me″ to form an oxide mixture; and

calcining the oxide mixture in an oxygen or air atmosphere to form the dual-phase ferrite.

18. The method of claim 17 , wherein the milling the ferrite precursor compounds comprises:

milling the ferrite precursor compounds comprising oxides of at least Co, Fe, Me, and Me′ to form a first oxide mixture; and

milling the ferrite precursor compounds comprising oxides of at least Fe, Me, and Me″ to form a second oxide mixture;

wherein the calcining comprises separately calcining the first oxide mixture and the second oxide mixture or calcining a mixture comprising the first oxide mixture and the second oxide mixture.

19. The method of claim 18 , wherein the calcining comprises separately calcining the first oxide mixture and the second oxide mixture to form separately calcined mixtures; and the method further comprises mixing the separately calcined mixture to form the dual-phase ferrite.

20. The method of claim 17 , further comprising post-annealing the ferrite in an oxygen or air atmosphere after the milling.

21. The method of claim 17 , wherein the calcining the calcined ferrite occurs at a calcining temperature of 800 to 1,300° C. for a calcining time of 0.5 to 20 hours.

22. A method of forming a composite, comprising:

forming a dual-phase ferrite according to the process of claim 17 ; and

mixing the dual-phase ferrite and a polymer.

Assignments (1)

Continuity (2)

References Cited (172)