Tdk Corporation

Keisuke Teranishi

Masashi Kitazaki

Makoto Ishizaki

Masahito Furukawa

Hideya Sakamoto

Taku Masai

Narumi Sato

Hiroki Mitsui

Kazuki Fukasawa

Miho Kato

Mingyu Chen

The vibration device includes a piezoelectric element having a connection terminal exposed from a main surface of the piezoelectric element, a first resin layer having conductivity and covering the connection terminal of the piezoelectric element to be electrically connected to the connection terminal, a wiring member overlapping the main surface of the piezoelectric element to cover the first resin layer, including a wire electrically connected to the first resin layer, and extending beyond one end of the piezoelectric element when viewed in a thickness direction of the piezoelectric element, and a second resin layer integrally covering the main surface of the piezoelectric element and the wiring member. The second resin layer includes a first layer in direct contact with the piezoelectric element and the wiring member, and a second layer covering the piezoelectric element and the wiring member via the first layer.

Vibration device

A piezoelectric composition comprises a plurality of crystal particles, wherein the piezoelectric composition includes bismuth, iron, barium, titanium, and oxygen; the crystal particle include a core and a shell having a contents of bismuth higher than that in the core and covering the core; and the total area of the cross sections of the cores exposed to the cross section of the piezoelectric composition is expressed as S, the total area of the cross sections of the shells exposed to the cross section of the piezoelectric composition is expressed as S, and 100&#xb7;S/(S+S) is 50 to 90.

Piezoelectric composition and piezoelectric device

The piezoelectric composition is represented by the following Chemical Formula (1):[BiFeO]-[BaTiO]-[BiAlO]&#x2003;&#x2003;(1)wherein 0.5&#x2264;x&#x2264;0.7995, 0.2&#x2264;y&#x2264;0.4, 0.0005&#x2264;z&#x2264;0.1, x+y+z=1, 0.96&#x2264;m&#x2264;1.04.

The piezoelectric composition is represented by the following Chemical Formula (1):[BiFeO]-[BaTiO]-[SrTiO]&#x2003;&#x2003;(1)wherein 0.5&#x2264;x&#x2264;0.8, 0.02&#x2264;y&#x2264;0.4, 0.02&#x2264;z&#x2264;0.2, x+y+z=1, and 0.96&#x2264;m&#x2264;1.04.

A piezoelectric composition comprises a plurality of crystal particles, wherein the piezoelectric composition includes bismuth, iron, barium, titanium, and oxygen; the crystal particles include a core and a shell covering the core; the average value of the contents of bismuth in the cores is expressed as C% by mass, the average value of the contents of bismuth in the shells is expressed as C% by mass, and the Cis lower than the C; and the number of all the particles comprised in the piezoelectric composition is expressed as N, the number of the crystal particles including the core and the shell is expressed as n, and n/N is 0.10 to 1.00.

The present invention aims to provide an excellent piezoelectric composition and an excellent piezoelectric element if the piezoelectric properties especially a high spontaneous polarization and a sufficiently high resistivity, the low pollution, the environment and the ecology are considered. In the piezoelectric composition, the main component contains the substance represented by the following formula with a perovskite-typed structure, (BiNa)(TiMgAl)O. Wherein, 0.01&#x2266;x&#x2266;0.8, 0.2&#x2266;y&#x2266;0.8, 0.01&#x2266;z&#x2266;0.6, 0.75&#x2266;m&#x2266;1.0, and x+y+z=1.

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Tokyo, Japan

Keisuke Teranishi