Novel multifferoic r-type hexaferrite, a composite and an article comprising the r-type hexaferrite, and a method of making the same

Patent metadata

Field	Value
Publication number	US-2023352222-A1
Application number	US-202118023168-A
Country	US
Kind code	A1
Filing date	Aug 25, 2021
Priority date	Aug 31, 2020
Publication date	Nov 2, 2023
Grant date	—

Abstract

In an aspect, an R-type ferrite has the formula: Me′3Me2TiFe12O25, wherein Me′ is at least one of Ba2+ or Sr2+ and Me is at least one of Co2+, Mg2+, Cu2+, or Zn2+. In another aspect, a composite or an article comprises the R-type ferrite. In yet another aspect, a method of making a R-type ferrite comprises milling ferrite precursor compounds comprising oxides of at least Fe, Ti, Me, and Me′, to form an oxide mixture; wherein Me′ comprises at least one of Ba2+ or Sr2+; Me is at least one of Co2+, Mg2+, Cu2+, or Zn2+; and calcining the oxide mixture in an oxygen or air atmosphere to form the R-type ferrite.

First claim

1 . An R-type ferrite, having the formula:
Me′ 3 Me 2 TiFe 12 O 25
wherein Me′ is at least one of Ba 2+ or Sr 2+ and Me is at least one of Co 2+ , Mg 2+ , Cu 2+ , or Zn 2+ .

2 . The R-type ferrite of claim 1 , wherein the Me′ comprises Ba 2+ .

3 . The R-type ferrite of claim 1 , wherein the R-type ferrite has the formula:
Ba 3 Co 2-x Me″ x TiFe 12 O 25
wherein Me″ is at least one of Mg 2+ , Cu 2+ , or Zn 2+ and x is 0 to 2.

4 . The R-type ferrite of claim 1 , wherein the R-type ferrite is multiferroic showing ferrimagnetic and ferroelectric ordering at greater than or equal to 23° C.

5 . The R-type ferrite of claim 1 , wherein the R-type ferrite has a permeability of greater than or equal to 2, at a frequency of 1 to 3 gigahertz.

6 . The R-type ferrite of claim 1 , wherein the R-type ferrite has a magnetic loss tangent tan δ μ of less than or equal to 0.8 at a frequency of 1 to 3 gigahertz.

7 . The R-type ferrite of claim 1 , wherein the R-type ferrite has a Snoek product of greater than or equal to 10 gigahertz, over the frequency range of 1 to 3 gigahertz.

8 . A composite comprising a polymer and the R-type ferrite of claim 1 .

9 . The composite of claim 8 , wherein the polymer comprises at least one of a fluoropolymer or a polyolefin.

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

11 . The article of claim 10 , wherein the article is an antenna, a filter, an inductor, a circulator, or an EMI suppressor.

12 . A method of making a R-type ferrite comprising:
milling ferrite precursor compounds comprising oxides of at least Fe, Ti, Me, and Me′, to form an oxide mixture; wherein Me′ comprises at least one of Ba 2+ or Sr 2+ ; Me is at least one of Co 2+ , Mg 2+ , Cu 2+ , or Zn 2+ ; and calcining the oxide mixture in an oxygen or air atmosphere to form the R-type ferrite.

13 . The method of claim 12 , wherein the milling occurs for greater than or equal to 4 hours; or at a mixing speed of greater than or equal to 300 revolutions per minute.

14 . The method of claim 12 , further comprising post-annealing the R-type ferrite in an oxygen or air atmosphere after the high energy milling; wherein the post-annealing occurs at an annealing temperature of 900 to 1,275° C., for an annealing time of 1 to 20 hours.

15 . The method of claim 12 , 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.

16 . The method of claim 12 , further comprising forming a composite comprising the R-type ferrite and a polymer.

Assignees

• Rogers Corp

Inventors

• Chen Yajie
• Li Qifan

Classifications

• H01F1/344 Primary

  Ferrites, e.g. having a cubic spinel structure (X2+O)(Y23+O3), e.g. magnetite Fe3O4 · CPC title

• C01G51/66 Primary

  containing alkaline earth metals, e.g. SrCoO3 · CPC title

• C08K3/22

  of metals · CPC title

• C01P2002/54

  one element only · CPC title

• C01P2006/42

  Magnetic properties · CPC title