US 12,408,556 B2
Piezoelectric stack, piezoelectric element, and method of manufacturing piezoelectric stack
Kenji Shibata, Hitachi (JP); Kazutoshi Watanabe, Hitachi (JP); and Fumimasa Horikiri, Hitachi (JP)
Assigned to SUMITOMO CHEMICAL COMPANY, LIMITED, Tokyo (JP)
Appl. No. 17/299,951
Filed by SUMITOMO CHEMICAL COMPANY, LIMITED, Tokyo (JP)
PCT Filed Nov. 14, 2019, PCT No. PCT/JP2019/044775
§ 371(c)(1), (2) Date Oct. 22, 2021,
PCT Pub. No. WO2020/116123, PCT Pub. Date Jun. 11, 2020.
Claims priority of application No. 2018-229831 (JP), filed on Dec. 7, 2018.
Prior Publication US 2023/0135208 A1, May 4, 2023
Int. Cl. H10N 30/853 (2023.01); C01G 33/00 (2006.01); H10N 30/076 (2023.01)
CPC H10N 30/8542 (2023.02) [C01G 33/006 (2013.01); H10N 30/076 (2023.02); C01P 2002/34 (2013.01); C01P 2002/54 (2013.01); C01P 2006/40 (2013.01); C01P 2006/60 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A piezoelectric stack, comprising:
a substrate;
an electrode film; and
a piezoelectric film comprising an alkali niobium oxide of a perovskite structure represented by a composition formula of (K1-xNax)NbO3 (0<x<1),
wherein the piezoelectric film further comprises a metallic element selected from the group consisting of copper and manganese at a concentration within a range of 0.2 at % to 2.0 at %, and
an average light transmittance through the piezoelectric film in a wavelength region of 380 nm or more and 1400 nm or less is 65% or more.