Laminate structure, piezoelectric element, and method of manufacturing piezoelectric element

A laminate structure comprising:

• a vibration plate having a thickness of more than 10 μm and 500 μm or less;
• a first structure that is bonded to a first surface of the vibration plate;
• and
• a second structure that is bonded to a second surface of the vibration plate,
• wherein the first structure includes a first silicon substrate and includes a first electrode layer, a first piezoelectric film, and a first facing electrode layer that are sequentially laminated on one surface of the first silicon substrate,
• the first facing electrode layer is disposed to face the first surface of the vibration plate and is bonded to the first surface of the vibration plate,
• the second structure includes a second silicon substrate and includes a second electrode layer, a second piezoelectric film, and a second facing electrode layer that are sequentially laminated on one surface of the second silicon substrate,
• the second facing electrode layer is disposed to face the second surface of the vibration plate and is bonded to the second surface of the vibration plate,
• the first piezoelectric film and the second piezoelectric film are formed of a perovskite type oxide, and
• pyrochlore type oxide layers having a thickness of 3 nm or more are formed in an interface between the first piezoelectric film and the first electrode layer and in an interface between the second piezoelectric film and the second electrode layer, respectively.