# US 7,408,292 B2 · Piezoelectric ceramic material multi-layered component and method for the production of a ceramic material

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- Number: US 7,408,292 B2
- Document ID: US7408292B2
- Status: Granted
- Kind: B2
- Application number: 10/574,209
- Filed: 2004-09-29
- Published: 2007-11-22
- Granted: 2008-08-05
- Earliest claimed: 2003-09-03
- Assignees: Epcos AG
- Inventors: Adalbert Feltz; Heinz Florian; Marion Ottlinger; Sigrid Ragossnig; Peter Sedlmaier
- Web page: https://patentgrep.com/patent/US7408292B2

## CPC

- C04B 35/491: based on lead zirconates and lead titanates {, e.g. PZT}
- H10N 30/097: by sintering
- H10N 30/8554: {Lead-zirconium titanate [PZT] based}
- C04B 2235/3224: Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
- C04B 2235/658: Atmosphere during thermal treatment
- C04B 2235/6584: at an oxygen percentage below that of air
- C04B 2235/6588: Water vapor containing atmospheres
- H10N 30/053: by integrally sintering piezoelectric or electrostrictive bodies and electrodes
- H10N 30/50: having a stacked or multilayer structure
- H10N 30/877: {Conductive materials}
- 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
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR

## Abstract

The invention relates to a piezoelectric ceramic material having the general composition ABO3 with at least a proportion of the PZT ceramic having a composition of the invention with Cu cations. The proportion of Zr and Ti cations is selected based upon the content of Cu cations, such that the ceramic material is tailored to the morphotropic phase boundary. The invention further discloses a method for producing a ceramic material of this type.

## Claims

### Claim 1

A piezoelectric ceramic material having a general composition of ABO3, the piezoelectric ceramic material comprising:
lead zirconate titanate having a perovskite lattice structure, wherein A stands for A positions in the perovskite lattice structure and B stands for B positions in the perovskite lattice structure, the lead zirconate titanate comprising at least a proportion of lead zirconate titanate of Pb1−3x/2−y/2SExγx/2−y/2CuIy(Zr0.5515−zTi0.4485+z)O3, wherein:
γ is a vacancy in a crystal lattice of the lead zirconate titanate;
a value of x is from about 0.01 to about 0.04;
a value of y is from about 0 to about the value of x divided by two;
SE is a rare-earth metal selected from the group consisting of La, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tu, Yb, Lu and Y,
x is determined by a valence of the rare-earth metal, and
z is selected based on the value of y such that the piezoelectric ceramic material corresponds to a morphotropic phase boundary.

### Claim 2 (depends on 1)

The piezoelectric ceramic material of claim 1, wherein Cu is in the perovskite lattice structure of the piezoelectric ceramic material at least partially in the A positions.

### Claim 3 (depends on 2)

The piezoelectric ceramic material of claim 2, wherein the Cu inserted in A positions is a monovalent, positive cation Cu+.

### Claim 4 (depends on 1)

The piezoelectric ceramic material of claim 1, wherein the piezoelectric ceramic material comprises Pb0.96Nd0.02Cu0.02(Zr0.5515Ti0.4485)O3.

### Claim 5 (depends on 1)

A method for producing a ceramic material according to claim 1, the method comprising:
preparing a materials mixture that includes copper oxide (CuO),
performing a calcination of the materials mixture under inert conditions in a reduced atmosphere under an oxygen partial pressure at which Cu and CuO are in equilibrium and coexist to form a calcined ceramic product,
grinding the calcined ceramic product;
homogenizing the calcined ceramic product; and
sintering the calcined ceramic product.

### Claim 6 (depends on 5)

The method of claim 5, wherein performing the calcination of the ceramic raw materials mixture comprises performing the calcination in a moist nitrogen atmosphere.

### Claim 7 (depends on 5)

The method of claim 5, wherein sintering the calcined ceramic product comprises sintering the calcined ceramic product in a moist nitrogen atmosphere.

### Claim 8 (depends on 1)

A method for producing a ceramic material according to claim 1, the method comprising:
performing a calcination of a materials mixture without a copper oxide (CuO) additive is to form a piezoceramic perovskite mixed-crystal phase material;
adding copper oxide Cu2O to a slurry, wherein the copper oxide is about evenly distributed throughout the slurry;
grinding the piezoceramic perovskite mixed-crystal phase material to form a ground material;
mixing the ground material with the slurry to form a ceramic mass; and
sintering the ceramic mass under inert conditions.

### Claim 9 (depends on 8)

The method of claim 8, wherein sintering the ceramic mass comprises sintering the ceramic mass in a moist nitrogen atmosphere.

### Claim 10 (depends on 1)

A multilayer piezoelectric component comprising:
a plurality of ceramic layers comprising the ceramic material of claim 1; and
a plurality of internal electrode layers, wherein the ceramic layers and the electrode layers alternate.

### Claim 11 (depends on 1)

The multilayer piezoelectric component of claim 1, wherein the internal electrode layers include at least a proportion of metallic copper.

### Claim 12 (depends on 1)

The multilayer piezoelectric component of claim 1, wherein a value of z is from about −0.15 to about +0.15.

### Claim 13 (depends on 1)

The multilayer piezoelectric component of claim 1, wherein a value of z is from about −0.016 to about +0.0205.