Piezoelectric film, piezoelectric stack, piezoelectric element, and method for producing piezoelectric stack
AssigneeSumitomo Chemical Company, Limited
InventorsToshiaki Kuroda, Kenji Shibata, Kazutoshi Watanabe, Takeshi Kimura
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Abstract
There is provided a piezoelectric film, being a polycrystalline film comprised of potassium sodium niobate; containing at least one metal element selected from a group consisting of Cu and Mn; and having 1.0 or less ratio of a concentration B of the metal element at grain boundaries of crystals, with respect to a concentration A of the metal element in a matrix phase of the crystals.
Claims16
A piezoelectric film, wherein the piezoelectric film is sputtered film comprising potassium sodium niobate and Mn;
- the piezoelectric film is a polycrystalline film comprising a matrix phase and crystalline grains;
- and
- a ratio of a concentration B of Mn at grain boundaries of the crystalline grains of the polycrystalline film, with respect to a concentration A of Mn in the matrix phase of the polycrystalline film is more than 0 and 1.0 or less.
A piezoelectric stack, comprising:
- a substrate;
- an electrode film on the substrate;
- and
- a piezoelectric film on the electrode film, the piezoelectric film being a sputtered film comprising of potassium sodium niobate and Mn,
- wherein the piezoelectric film is a polycrystalline film comprising a matrix phase and crystalline grains;
- 80% or more of the crystalline grains of the piezoelectric film are oriented in (001) direction with respect to a surface of the substrate;
- and
- a ratio of a concentration B of Mn at grain boundaries of the crystalline grains of the piezoelectric film, with respect to a concentration A of Mn in the matrix phase of the crystals, is more than 0 and 1.0 or less.
A piezoelectric element, comprising:
- a substrate;
- a bottom electrode film provided on the substrate;
- a piezoelectric film at the bottom electrode film, the piezoelectric film being a sputtered film comprising potassium sodium niobate and Mn;
- and
- a top electrode film on the piezoelectric film,
- wherein
- the piezoelectric film is a polycrystalline film comprising a matrix phase and crystalline grains;
- 80% or more of the crystalline grains of the piezoelectric film are oriented in (001) direction with respect to a surface of the substrate;
- and
- a ratio of a concentration B of Mn at grain boundaries of the crystalline grains of the piezoelectric film, with respect to a concentration A of Mn in the matrix phase of the crystals, is more than 0 and 1.0 or less.
A method for producing a piezoelectric stack, comprising:
- depositing an electrode film on a substrate;
- and
- depositing by sputtering a piezoelectric film on the electrode film, wherein the piezoelectric film comprises potassium sodium niobate and Mn,
- the piezoelectric film is a polycrystalline film comprising a matrix phase and crystalline grains;
- 80% or more of the crystalline grains of the piezoelectric film are oriented in (001) direction with respect to a surface of the substrate;
- and
- the piezoelectric film has a concentration B of Mn at grain boundaries of the crystalline grains of the piezoelectric film, with respect to a concentration A of Mn in the matrix phase of the piezoelectric film.
Dependencies are inferred from the claim text.