Inductor including alpha″-Fe16Z2 or alpha″-Fe16(NxZ1-x)2, where Z includes at least one of C, B, or O

Patent metadata

Field	Value
Publication number	US-10002694-B2
Application number	US-201514821520-A
Country	US
Kind code	B2
Filing date	Aug 7, 2015
Priority date	Aug 8, 2014
Publication date	Jun 19, 2018
Grant date	Jun 19, 2018

Abstract

An inductor may include a magnetic material that may include α″-Fe 16 (N x Z 1-x ) 2 or α′-Fe 8 (N x Z 1-x ), or a mixture of at least one of α″-Fe 16 N 2 or α′-Fe 8 N and at least one of α″-Fe 16 Z 2 or α′-Fe 8 Z, where Z includes at least one of C, B, or O, and x is a number greater than zero and less than one. In some examples, the magnetic material may include a relatively high magnetic saturation, such as greater than about 200 emu/gram, greater than about 242 emu/gram, or greater than about 250 emu/gram. In addition, in some examples, the magnetic material may include a relatively low coercivity or magnetocrystalline anisotropy. Techniques for forming the inductor including the magnetic material are also described.

First claim

What is claimed is:

1. A device comprising:
a substrate;
a dielectric or insulator layer on the substrate; and
an inductor on the dielectric or insulator layer, wherein the inductor comprises a magnetic material comprising at least one of:
a plurality of α″-Fe 16 (N x Z 1-x ) 2 or α′-Fe 8 (N x Z 1-x ) phase domain, wherein x is a number greater than zero and less than one, and wherein respective [001] axes of the plurality of α″-Fe 16 (N x Z 1-x ) 2 or α′-Fe 8 (N x Z 1-x ) phase domains are randomly distributed within the magnetic material; or
a plurality of α″-Fe 16 N 2 or α′-Fe 8 N phase domains and a plurality of α″-Fe 16 Z 2 or α′-Fe 8 Z phase domains, wherein Z includes at least one of C, B, or O, and wherein respective [001] axes of the plurality of α″-Fe 16 N 2 or α′-Fe 8 N phase domains and respective [001] axes of the plurality of α″-Fe 16 Z 2 or α′-Fe 8 Z phase domains are randomly distributed within the magnetic material.

2. The device of claim 1 , wherein the inductor comprises a core, and wherein the core comprises the magnetic material.

3. The device of claim 2 , wherein the core comprises a substantially planar spiral portion.

4. The device of claim 2 , wherein the core comprises a plurality of substantially planar spiral portions.

5. The device of claim 2 , wherein the magnetic material comprises the plurality of α″-Fe 16 (N x Z 1-x ) 2 or α′-Fe 8 (N x Z 1-x ) phase domains, and wherein x is equal to about 0.5.

6. The device of claim 2 , wherein the magnetic material comprises the plurality of α″-Fe 16 (N x Z 1-x ) 2 or α′-Fe 8 (N x Z 1-x ) phase domain, and wherein x is equal to about 0.4667.

7. The device of claim 2 , wherein Z consists of C.

8. The device of claim 2 , wherein the magnetic material comprises a saturation magnetization of at least about 200 emu/gram.

9. The device of claim 2 , wherein the magnetic material comprises a saturation magnetization of greater than about 250 emu/gram.

10. The device of claim 2 , wherein the magnetic material comprises a magnetic coercivity of less than or equal to about 10 Oerstads.

11. The device of claim 2 , wherein the magnetic material comprises the plurality of α″-Fe 16 (N x Z 1-x ) 2 or α′-Fe 8 (N x Z 1-x ) phase domains, and wherein at least about 35 volume percent of the magnetic material is the plurality of α″-Fe 16 (N x Z 1-x ) 2 or α′-Fe 8 (N x Z 1-x ) phase domains.

12. The device of claim 2 , wherein at least about 60 volume percent of the magnetic material is the plurality of α″-Fe 16 (N x Z 1-x ) 2 or α′-Fe 8 (N x Z 1-x ) phase domains.

13. The device of claim 2 , wherein the magnetic material comprises the plurality of α″-Fe 16 N 2 or α′-Fe 8 N phase domains and the plurality of α″-Fe 16 Z 2 or α′-Fe 8 Z phase domains, and wherein the plurality of α″-Fe 16 N 2 or α′-Fe 8 N phase domains and the plurality of α″-Fe 16 Z 2 or α′-Fe 8 Z phase domains together form at least about 35 volume percent of the magnetic material.

14. The device of claim 2 , wherein the magnetic material comprises the plurality of α″-Fe 16 N 2 or α′-Fe 8 N phase domains and the plurality of α″-Fe 16 Z 2 or α′-Fe 8 Z phase domains, and wherein the plurality of α″-Fe 16 N 2 or α′-Fe 8 N phase domains and the plurality of α″-Fe 16 Z 2 or α′-Fe 8 Z phase domains together form at least about 60 volume percent of the magnetic material.

15. The device of claim 2 , further comprising an impedance matching circuit, wherein the impedance matching circuit comprises the inductor.

16. The device of claim 2 , further comprising a low pass filter, wherein the low pass filter comprises the inductor.

17. The device of claim 2 , further comprising an AC-DC converter, wherein the AC-DC converter comprises the inductor.

18. The device of claim 2 , further comprising an antenna, wherein the antenna comprises a magnetic material comprising at least one of:
at least one α″-Fe 16 (N x Z 1-x ) 2 or α′-Fe 8 (N x Z 1-x ) phase domains, wherein x is a number greater than zero and less than one; or
at least one α″-Fe 16 N 2 or α′-Fe 8 N phase domain and at least one α″-Fe 16 Z 2 or α′-Fe 8 Z phase domain, wherein Z includes at least one of C, B, or O.

19. The device of claim 18 , wherein the antenna comprises a multiband antenna.

20. The device of claim 2 , further comprising a radio frequency energy harvesting device, wherein the radio frequency energy harvesting device comprises the inductor.

21. A method comprising:
forming a dielectric or insulator layer on a substrate; and
forming an inductor on the dielectric or insulator layer, wherein a core of the inductor comprises a magnetic material comprising at least one of:
a plurality of α″-Fe 16 (N x Z 1-x ) 2 phase domains, wherein x is a number greater than zero and less than one, and wherein respective [001] axes of the plurality of α″-Fe 16 (N x Z 1-x ) 2 phase domains are randomly distributed within the magnetic material; or
a plurality of α″-Fe 16 N 2 phase domain and plurality of α″-Fe 16 Z 2 phase domains, wherein Z includes at least one of C, B, or O, and wherein respective [001] axes of the plurality of α″-Fe 16 N 2 phase domains and respective [001] axes of the plurality of α″-Fe 16 N 2 phase domains are randomly distributed within the magnetic material.

22. The method of claim 21 , wherein forming the inductor comprises:
heating an iron source to form a vapor comprising an iron-containing compound;
depositing iron from the vapor comprising the iron-containing compound, nitrogen from a vapor comprising a nitrogen-containing compound, and at least one of carbon, boron, or oxygen from a vapor comprising the compound containing the at least one of carbon, boron, or oxygen on the dielectric or insulator layer to form a layer comprising iron, nitrogen, and the at least one of carbon, boron, or oxygen; and
annealing the layer comprising iron, nitrogen, and the at least one of carbon, boron, or oxygen to form the inductor.

23. The method of claim 21 , wherein forming the inductor comprises:
submerging a dielectric or insulator layer on a substrate in a coating solution comprising a nitrogen-containing solvent, an iron source, and a carbon source, wherein the coating solution is saturated with the iron source at a first temperature above a liquidus temperature of an iron-carbon-nitrogen mixture to be deposited from the coating solution;
cooling the coating solution to a second temperature to form a supersaturated coating solution, wherein the second temperature is below the liquidus temperature of the iron-carbon-nitrogen mixture;
maintaining the substrate in the supersaturated coating solution to allow a coating comprising iron, carbon, and nitrogen to form on the substrate; and
annealing the coating comprising iron, carbon, and nitrogen to form the inductor.

24. The method of claim 22 , further comprising:
defining a depression in the dielectric or insulator layer corresponding to a shape of at least part of the inductor;
wherein forming the inductor on the dielectric or insulator layer comprises forming the inductor in the depression.

25. The method of claim 23 , further comprising:
defining a depression in the dielectric or insulator layer corresponding to a shape of at least part of the inductor;
wherein forming the inductor on the dielectric or insulator layer comprises forming the inductor in the depression.

26. The method of claim 22 , wherein forming an inductor

Assignees

• Univ Minnesota

Inventors

• Wang Jian-Ping
• Jiang Yanfeng
• Mehedi Md Aminul

Classifications

• H01F41/046

  structurally combined with ferromagnetic material · CPC title

• H01F1/0302 Primary

  characterised by unspecified or heterogeneous hardness or specially adapted for magnetic hardness transitions · CPC title

• H01F17/0006

  Printed inductances (printed coils for dynamo-electric machines H02K3/26; printed circuits H05K) · CPC title

• H01F1/065

  obtained by a reduction · CPC title

• H01F17/0013

  with stacked layers · CPC title