US 12,356,861 B2
Piezoelectric thin film, piezoelectric thin film element and piezoelectric transducer
Junpei Morishita, Tokyo (JP)
Assigned to TDK Corporation, Tokyo (JP)
Filed by TDK Corporation, Tokyo (JP)
Filed on Feb. 26, 2024, as Appl. No. 18/586,852.
Application 18/586,852 is a division of application No. 17/208,051, filed on Mar. 22, 2021, granted, now 12,052,922.
Claims priority of application No. 2020-056476 (JP), filed on Mar. 26, 2020; and application No. 2020-180666 (JP), filed on Oct. 28, 2020.
Prior Publication US 2024/0237540 A1, Jul. 11, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H10N 30/00 (2023.01); H10N 30/076 (2023.01); H10N 30/853 (2023.01); H10N 30/87 (2023.01)
CPC H10N 30/708 (2024.05) [H10N 30/076 (2023.02); H10N 30/8536 (2023.02); H10N 30/878 (2023.02)] 15 Claims
OG exemplary drawing
 
1. A piezoelectric thin film containing:
an oxide having a perovskite structure,
wherein the piezoelectric thin film contains a tetragonal crystal 1 of the oxide and a tetragonal crystal 2 of the oxide,
a (001) plane of the tetragonal crystal 1 is oriented in a normal direction of a surface of the piezoelectric thin film,
a (001) plane of the tetragonal crystal 2 is oriented in the normal direction of the surface of the piezoelectric thin film,
an interval of the (001) plane of the tetragonal crystal 1 is c1,
an interval of a (100) plane of the tetragonal crystal 1 is a1,
an interval of the (001) plane of the tetragonal crystal 2 is c2,
an interval of a (100) plane of the tetragonal crystal 2 is a2,
c2/a2 is more than c1/a1,
a peak intensity of diffracted X-rays of the (001) plane of the tetragonal crystal 1 is I1,
a peak intensity of diffracted X-rays of the (001) plane of the tetragonal crystal 2 is I2, and
I2/(I1+I2) is from 0.50 to 0.90.