| 摘要 |
A surface acoustic wave element includes a LiNbxTa1-xO3 ("x' is 0 or more and 1 or less) film on a (012) sapphire substrate, in which a Love wave is propagated as a surface acoustic wave in a specific direction of the LiNbxTa1-xO3 film. Preferably, a crystal axis of the sapphire substrate and a crystal axis of a (012) LiNbxTa1-xO3 film ("x' is 0 or more and 1 or less) are parallel to each other; a surface acoustic wave propagation direction is within a range of ±20 degrees around an axis vertical to a C-axis projection line direction of a crystal axis of the sapphire substrate or the (012) LiNbxTa1-xO3 film. Alternatively, a C-axis projection line direction of a crystal axis of the sapphire substrate and a C-axis direction of a crystal axis of a (100) LiNbxTa1-xO3 film ("x' is 0 or more and 1 or less) are parallel to each other, and the surface acoustic wave propagation direction is within a range of ±35 degrees around an axis vertical to a C-axis projection line direction of a crystal axis of the sapphire substrate. A piezoelectric substrate preferably has an intermediate layer including of a metal or a metal oxide between the sapphire substrate and the (100) LiNbxTa1-xO3 ("x' is 0 or more and 1 or less). |
