Piezoelectric film and the use thereof

To provide a piezoelectric film having a higher depolarization temperature Td. The piezoelectric film according to the present invention includes: only a (001) orientation (Nax1, Biy1) TiO0.5x1 + 1.5y1 + 2-BaTiO3 layer (14); and only a (001) orientation (Nax2, Biy2) TiO0 .5x2 + 1.5y2 + 2-BaTiO3 layer (15), wherein, 0.28≤x1≤0.43,0.49≤y1≤0.60,0.30≤x2≤0.46,0.51≤y2≤0.63. (Nax1, Biy1) TiO0.5x1 + 1.5y1 + 2-BaTiO3 layer (14) containing nickel, and has a molar ratio of Ti more than 0.02 Ni /.