Compositions and materials for electronic applications

Patent metadata

Field	Value
Publication number	US-9505632-B2
Application number	US-201414452340-A
Country	US
Kind code	B2
Filing date	Aug 5, 2014
Priority date	Sep 22, 2010
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

Embodiments disclosed herein relate to using cobalt (Co) to fine tune the magnetic properties, such as permeability and magnetic loss, of nickel-zinc ferrites to improve the material performance in electronic applications. The method comprises replacing nickel (Ni) with sufficient Co +2 such that the relaxation peak associated with the Co +2 substitution and the relaxation peak associated with the nickel to zinc (Ni/Zn) ratio are into near coincidence. When the relaxation peaks overlap, the material permeability can be substantially maximized and magnetic loss substantially minimized. The resulting materials are useful and provide superior performance particularly for devices operating at the 13.56 MHz ISM band.

First claim

What is claimed is:

1. An RF device comprising:
a composition represented by the formula
Ni 1-w-x-y-z Zn w Co x Mn y Cu z Fe 2-a O 4-1.5a ,

w being greater than or equal to 0.2 and less than or equal to 0.6;
x being greater than or equal to 0 and less than or equal to 0.2;
y being greater than or equal to 0 and less than or equal to 0.2;
z being greater than or equal to 0 and less than or equal to 0.2;
a being greater than or equal to 0 and less than or equal to 0.2; and
said RF device operates in the 13.56 MHz band.

2. The RF device of claim 1 wherein z=0 in the formula representing the composition.

3. The RF device of claim 1 wherein y=0 in the formula representing the composition.

4. An RF device comprising:
a composition represented by the formula
Ni 1-w-x-y-z Zn w Co x Mn y Cu z Fe 2-a O 4-1.5a ,

w being greater than or equal to 0.2 and less than or equal to 0.6;
x being greater than or equal to 0 and less than or equal to 0.2;
y being greater than or equal to 0 and less than or equal to 0.2;
z being greater than or equal to 0 and less than or equal to 0.2;
a being greater than or equal to 0 and less than or equal to 0.2; and
said RF device is an antenna.

5. The RF device of claim 4 wherein z=0 in the formula representing the composition.

6. The RF device of claim 4 wherein y=0 in the formula representing the composition.

7. An RF device comprising:
a modified nickel-zinc ferrite composition represented by the formula
Ni 1-x-y Zn x Co y Fe 2 O 4 ,

x being greater than or equal to 0.2 and less than 0.6, and y being greater than or equal zero and less than 0.2; and
said RF device is selected from the group consisting of RFID tags, biomedical sensors, and RF antennas.

8. An RF device comprising:
a modified nickel-zinc ferrite composition represented by the formula
Ni 1-x-y Zn x Co y Fe 2 O 4 ,

x being greater than or equal to 0.2 and less than 0.6, and y being greater than or equal zero and less than 0.2; and
said RF device operates in the 13.56 MHz band.

Assignees

• Skyworks Solutions Inc

Inventors

• Hill Michael David
• Cruickshank David Bowie
• Anderson Kelvin M

Classifications

• C04B2235/3275

  Cobalt oxides, cobaltates or cobaltites or oxide forming salts thereof, e.g. bismuth cobaltate, zinc cobaltite · CPC title

• C01P2006/32

  Thermal properties · CPC title

• C01G49/0018

  Mixed oxides or hydroxides, (C01G49/0009 takes precedence) · CPC title

• C04B2235/81

  Materials characterised by the absence of phases other than the main phase, i.e. single phase materials · CPC title

• C04B2235/3281

  Copper oxides, cuprates or oxide-forming salts thereof, e.g. CuO or Cu2O · CPC title