Piezoelectric ceramic, method for making the same, piezoelectric element, liquid discharge head, and ultrasonic motor

Patent metadata

Field	Value
Publication number	US-9130168-B2
Application number	US-201313853840-A
Country	US
Kind code	B2
Filing date	Mar 29, 2013
Priority date	Nov 30, 2009
Publication date	Sep 8, 2015
Grant date	Sep 8, 2015

Abstract

A piezoelectric ceramic that includes barium titanate and 0.04 mass % or more and 0.20 mass % or less manganese relative to barium titanate. The piezoelectric ceramic is composed of crystal grains. The crystal grains include crystal grains A having an equivalent circular diameter of 30 μm or more and 300 μm or less and crystal grains B having an equivalent circular diameter of 0.5 μm or more and 3 μm or less. The crystal grains A and the crystal grains B individually form aggregates and the aggregates of the crystal grains A and the aggregates of the crystal grains B form a sea-island structure.

First claim

What is claimed is:

1. A method for making a piezoelectric ceramic, comprising:
sintering a mixture at least containing barium titanate particles 1 containing 0.05 mass % or more and 2.0 mass % or less manganese on a metal basis and barium titanate particles 2 containing less than 0.04 mass % manganese on a metal basis,
wherein the piezoelectric ceramic comprises:
barium titanate; and
0.04 mass % or more and 0.20 mass % or less manganese relative to barium titanate,
wherein the piezoelectric ceramic is composed of crystal grains,
the crystal grains include crystal grains A having an equivalent circular diameter of 30 μm or more and 300 μm or less and crystal grains B having an equivalent circular diameter of 0.5 μm or more and 3 μm or less, and
the crystal grains A and the crystal grains B individually form aggregates and the aggregates of the crystal grains A and the aggregates of the crystal grains B form a sea-island structure.

2. The method according to claim 1 , wherein the content of the barium titanate particles 1 in the mixture is 2 mass % or more and 90 mass % or less.

Assignees

• Canon Kk

Inventors

• Kubota Makoto
• Furuta Tatsuo
• Saito Hiroshi
• Ifuku Toshihiro
• Takeda Kenichi
• Fukui Tetsuro

Classifications

• C04B2235/5445

  submicron sized, i.e. from 0,1 to 1 micron · CPC title

• C04B35/62655

  Drying, e.g. freeze-drying, spray-drying, microwave or supercritical drying · CPC title

• C04B35/62886

  by wet chemical techniques · CPC title

• H02N2/106

  Langevin motors · CPC title

• H01L41/1871 Primary

  Electricity · mapped topic