Low-temperature co-firing of multilayer textured piezoelectric ceramics with inner electrodes

Patent metadata

Field	Value
Publication number	US-10224476-B2
Application number	US-201314376319-A
Country	US
Kind code	B2
Filing date	Feb 1, 2013
Priority date	Feb 1, 2012
Publication date	Mar 5, 2019
Grant date	Mar 5, 2019

Abstract

Textured PMN-PZT fabricated by templated grain growth (TGG) method has a piezoelectric coefficient (d) of 3 to 5 times that of its random counterpart. By combining this TGG method with low-temperature co-firing ceramics (LTCC) techniques, co-fired multilayer textured piezoelectric ceramic materials with inner electrodes were produced at a temperature as low as 925° C., which silver could be used. Trilayer PMN-PZT ceramics prepared by this method show a strain increase of 2.5 times, a driving voltage decrease of 3 times, and an equivalent piezoelectric coefficient (d*) improvement of 10 to 15 times that of conventional random ceramic counterparts. Further, a co-fired magnetostrictive/piezoelectric/magnetostrictive laminate structure with silver inner electrode was also synthesized. The integration of textured piezoelectric microstructure with the cost-effective low-temperature co-fired layered structure achieves strong magnetoelectric coupling. These new materials have promising applications including as actuators, ultrasonic transducers, and use in energy harvesters.

First claim

The invention claimed is:

1. A composition comprising a co-fired multilayer textured PMN-PZT or a co-fired multilayer textured PMN-PT ceramic with BaTiO 3 platelets oriented within the ceramic to a desired degree, wherein the ceramic has a piezoelectric coefficient d 33 ranging from 1000-3000 pC/N and a degree of orientation of 90% or more;
wherein the PMN-PZT ceramic comprises the formula 0.4Pb(Mg 1/3 Nb 2/3 )O 3 -0.25PbZrO 3 -0.35PbTiO 3 (40PMN-25PZ-35PT).

2. A composition comprising a co-fired multilayer textured PMN-PZT or a co-fired multilayer textured PMN-PT ceramic with BaTiO 3 platelets oriented within the ceramic to a desired degree, wherein the ceramic has a piezoelectric coefficient d 33 ranging from 1000-3000 pC/N and a degree of orientation of 90% or more;
wherein the BaTiO 3 platelets have an aspect ratio of from 5-20.

3. A composition comprising a co-fired multilayer textured PMN-PZT or a co-fired multilayer textured PMN-PT ceramic with BaTiO 3 platelets oriented within the ceramic to a desired degree, wherein the ceramic has a piezoelectric coefficient d 33 ranging from 1000-3000 pC/N and a degree of orientation of 90% or more;
wherein the composition comprises multiple layers and has a strain increase of greater than 2 times that of a random oriented PMN-PZT of the same empirical formula.

4. A composition comprising a co-fired multilayer textured PMN-PZT or a co-fired multilayer textured PMN-PT ceramic with BaTiO 3 platelets oriented within the ceramic to a desired degree, wherein the ceramic has a piezoelectric coefficient d 33 ranging from 1000-3000 pC/N and a degree of orientation of 90% or more;
wherein the composition comprises multiple layers and has a decrease in driving voltage of greater than 2 times that of a random oriented PMN-PZT with the same empirical formula.

5. A composition comprising a co-fired multilayer textured PMN-PZT or a co-fired multilayer textured PMN-PT ceramic with BaTiO3 platelets oriented within the ceramic to a desired degree, wherein the ceramic has a piezoelectric coefficient d33 ranging from 1000-3000 pC/N and a degree of orientation of 90% or more;
wherein the composition further comprises at least one internal electrode.

6. The composition of claim 5 , wherein at least one of the internal electrodes is silver.

7. The composition of claim 5 , wherein preparation of the composition involves co-firing of the piezoelectric and at least one of the internal electrodes to no more than 450° C. for about 2 hours and sintering at up to 930° C.

8. A composition comprising a co-fired multilayer textured PMN-PZT or a co-fired multilayer textured PMN-PT ceramic with BaTiO3 platelets oriented within the ceramic to a desired degree, wherein the ceramic has a piezoelectric coefficient d33 ranging from 1000-3000 pC/N and a degree of orientation of 90% or more;
wherein the composition comprises more than one layer, one of which is a magnetostrictive layer.

9. A composition comprising a co-fired multilayer textured PMN-PZT or a co-fired multilayer textured PMN-PT ceramic with BaTiO 3 platelets oriented within the ceramic to a desired degree, said composition characterized by having giant self-biased magnetoelectric coupling, wherein the ceramic has a piezoelectric coefficient d 33 ranging from 1000-3000 pC/N and a degree of orientation of 90% or more.

Assignees

• Virginia Tech Intellectual Properties Inc

Inventors

• Yan Yongke
• Priya Shashank

Classifications

• H01L41/20 Primary

  Electricity · mapped topic

• H01L41/083

  Electricity · mapped topic

• C04B2235/787

  Oriented grains · CPC title

• C04B2235/3249

  containing also titanium oxide or titanates, e.g. lead zirconate titanate (PZT) · CPC title

• H01L41/16

  Electricity · mapped topic