Ferromagnetic materials

• US 5,382,304 A
• Filed: 10/19/1992
• Issued: 01/17/1995
• Est. Priority Date: 03/16/1990
• Status: Expired due to Term

• Current Assignee: Lujack Systems LLC (Intellectual Ventures LLC)
• Original Assignee: The secretary of state for defence in her Britannic Majesty's Government of the United Kingdom of Great Britain And Northern Ireland
• Inventors: Cockayne, Brian, MacEwan, William R., Harris, Ivor R., Smith, Nigel A.
• Primary Examiner(s): WYSZOMIERSKI, GEORGE P
• Application Number:
  US07/937,865
• Time in Patent Office: 820 Days
• Field of Search: 148/306, 420/8, 420/77, 420/84, 420/103
• US Class Current: 148/306
• CPC Class Codes: H01F 1/0311 Compounds H01F1/0304 takes precedence

Abstract

This invention provides a ferromagnetic material Fe₆₀ M_x N_y where M is at least one element selected from Al, Ga, In and Tl, N is at least one element selected from P, As, Sb and Bi, x has a range of 1≦×≦39 and x+y=40 and excluding Fe₆₀ Ga_X AS_y. A preferred ferromagnetic material is Fe₆₀ Ga_x As_y , preferably when x has a range of 3≦×≦37, more preferably when x has a range of 20≦×≦37, and even more preferably when x has a range of 30≦×≦37. Typically, ferromagnetic materials of this type can be homogenised by annealing or melt spinning. Melt spun Fe₆₀ Ga_x As_y can show Curie Temperatures (T_c) of about 470° C. and saturation magnestions of about 89 emu/g. Typically a ferromagentic material of the Fe₆₀ M_x N_y has a B8₂ type structure.

Claims

1. A ferromagnetic material having a B8₂ crystal structure consisting essentially of Fe₆₀ M_x N_y where M is at least one element selected from the group consisting of Al, Ga, In and Tl;

N is at least one element selected from the group consisting of As, Sb and Bi;

where x has a range of 1≦

×

≦

39; and

where x+y=40 and wherein when M is Ga, N is not As.

2. The ferromagnetic material according to claim 2 where M is Ga and N is Sb.

3. The ferromagnetic material according to claim 2 where x has a range of 3≦

×

≦

37.

4. The ferromagnetic material according to claim 3 where x has a range of 20≦

×

≦

37.

5. The ferromagnetic material according to claim 3 where x has a range of 20≦

×

≦

37 .

6. The ferromagnetic material according to claim 4 where the material has been homogenized.

7. The ferromagnetic material according to claim 6 where homogenization has been achieved by annealing.

8. The ferromagnetic material according to claim 7 where annealing has been carried at a temperature of between 600°

C. and 900°

C.

9. The ferromagnetic material according to claim 6 where homogenization has been achieved by melt spinning.

10. A ferromagnetic material having a B8₂ crystal structure consisting essentially of Fe₆₀ M_x N_y where M is at least one element selected from the group consisting of Al, Ga, In and Tl;

N is at least one element selected from the group consisting of As, Sb and Bi;

where x has a range of 30≦

×

≦

39; and

where x+y=40 and wherein when M is Ga, N is not As.