# US 2013/0153812 A1 · Lead-free piezoelectric materials with enhanced fatigue resistance

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- Number: US 2013/0153812 A1
- Document ID: US20130153812A1
- Status: Published application
- Kind: A1
- Application number: 13/819,946
- Filed: 2010-09-30
- Published: 2013-06-20
- Earliest claimed: 2010-09-30
- Assignees: Hewlett-Packard Development Company, L.P.
- Inventors: Yu Hong Jeon; David Cann; Eric Patterson; Parkpoom Jarupoom; Brady Gibbons; Peter Mardilovich
- Web page: https://patentgrep.com/patent/US20130153812A1

## CPC

- H10N 30/8561: {Bismuth-based oxides}
- C04B 35/475: based on bismuth titanates
- C04B 35/62615: {High energy or reactive ball milling}
- C04B 35/6263: {characterised by their solids loadings, i.e. the percentage of solids}
- C04B 2235/3201: Alkali metal oxides or oxide-forming salts thereof
- C04B 2235/3206: Magnesium oxides or oxide-forming salts thereof
- C04B 2235/3279: Nickel oxides, nickalates, or oxide-forming salts thereof
- C04B 2235/768: Perovskite structure ABO3
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE

## Abstract

A lead-free piezoelectric ceramic material has the general chemical formula xBi(A0.5Ti0.5)O3-y(Bi0.5K0.5)TiO3-z(Bi0.5Na0.5)TiO3, wherein x+y+z=1, x≠0, and A=Ni or Mg.

## Claims

### Claim 1

A lead-free piezoelectric ceramic material having the general chemical formula:
xBi(A0.5Ti0.5)O3-y(Bi0.5K0.5)TiO3, wherein x+y=1;
xBi(A0.5Ti0.5)O3-z(Bi0.5Na0.5)TiO3, wherein x+z=1; or
xBi(A0.5Ti0.5)O3-y(Bi0.5K0.5)TiO3-z(Bi0.5Na0.5)TiO3, wherein x+y+z=1;
wherein A=Mg or Ni, and x, y, z≠0.

### Claim 2 (depends on 1)

The ceramic material of claim 1, wherein said material comprises a solid solution having a stable perovskite structure at standard atmospheric conditions.

### Claim 3 (depends on 2)

The lead-free piezoelectric ceramic material of claim 2, wherein 0.01≦x≦0.70.

### Claim 4 (depends on 1)

The lead-free piezoelectric ceramic material of claim 1, having the general chemical formula xBi(A0.5Ti0.5)O3-y(Bi0.5K0.5)TiO3 or xBi(A0.5Ti0.5)O3-y(Bi0.5Na0.5)TiO3, wherein x+y=1, A is Ni or Mg, and 0<x≦0.50.

### Claim 5 (depends on 1)

The lead-free piezoelectric ceramic material of claim 1, having the general chemical formula xBi(A0.5Ti0.5)O3-y(Bi0.5K0.5)TiO3-z(Bi0.5Na0.5)TiO3, wherein x+y+z=1, A is Ni or Mg, and 0.01≦x≦0.99.

### Claim 6 (depends on 1)

The lead-free piezoelectric ceramic material of claim 1, wherein said ceramic material has a piezoelectric strain coefficient d33 equal to or exceeding that of a lead zirconate titanate perovskite.

### Claim 7 (depends on 1)

The lead-free piezoelectric ceramic material of claim 1, wherein said ceramic material has a maximum piezoelectric d33 value in the range of about 200 pm/V to about 700 pm/V.

### Claim 8 (depends on 7)

The lead-free piezoelectric ceramic material of claim 7, wherein said ceramic material has a maximum piezoelectric d33 value in the range of about 300 pm/V to about 400 pm/V.

### Claim 9 (depends on 1)

The lead-free piezoelectric ceramic material of claim 1, wherein said ceramic material has a maximum electromechanical strain value in the range of about 0.20 percent to about 0.35 percent.

### Claim 10 (depends on 1)

The lead-free piezoelectric ceramic material of claim 1, wherein said ceramic material has fatigue resistance equal to or exceeding that of a lead zirconate titanate perovskite.

### Claim 11 (depends on 1)

The lead-free piezoelectric ceramic material of claim 1 having a Curie temperature (Tc) in the range of about 100° C. to about 500° C.

### Claim 12 (depends on 13)

The lead-free piezoelectric ceramic material of claim 13 wherein the Tc is in the range of about 300° C. to about 400° C.