High-performance piezoelectric device with piezoelectric element
A piezoelectric element includes: a piezoelectric body having a first surface and a second surface that are different from each other; a first electrode provided at the first surface; and a second electrode provided at the second surface. The piezoelectric body contains a helical chiral polymer crystal having an orientation axis as a crystal axis, the orientation axis is uniaxially oriented in a manner of intersecting both the first surface and the second surface, and a degree of orientation of the orientation axis in the piezoelectric body is 0.80 or more.
1 . A piezoelectric element comprising:
a piezoelectric body having a first surface and a second surface, wherein the second surface is different from the first surface;
a first electrode provided at the first surface; and
a second electrode provided at the second surface, wherein
the piezoelectric body contains a polylactic acid crystal,
the polylactic acid crystal has a helical structure and has a unit cell having an a axis, a b axis, and a c axis as crystal axes,
lengths of the crystal axes satisfy a relationship of b axis<a axis<c axis,
the c axis is parallel to an advance axis of the helical structure, and
an orientation axis is the b axis,
the orientation axis is uniaxially oriented in a manner of intersecting both the first surface and the second surface, and
a degree of orientation of the orientation axis in the piezoelectric body is 0.80 or more.
2 . A piezoelectric device comprising:
a substrate,
a support portion, and
the piezoelectric element according to claim 1 .
3 . The piezoelectric element according to claim 1 , wherein when the piezoelectric body is subjected to a θ-2θ measurement by X-ray diffraction and a θ-2θ profile is obtained, the θ-2θ profile has a peak in a range in which a diffraction angle 2θ is 13.5° or more and less than 15.5°.
4 . A piezoelectric device comprising:
a substrate,
a support portion, and
the piezoelectric element according to claim 3 .
5 . The piezoelectric element according to claim 1 , wherein the piezoelectric body is an injection molded body.
6 . A piezoelectric device comprising:
a substrate,
a support portion, and
the piezoelectric element according to claim 5 .
7 . The piezoelectric element according to claim 3 , wherein the piezoelectric body is an injection molded body.
8 . A piezoelectric device comprising:
a substrate,
a support portion, and
the piezoelectric element according to claim 7 .