Piezoelectric ceramic composition and piezoelectric actuator
AssigneeKYOCERA Corporation
InventorsShuhei Tabata, Takeshi Hirayama, Gen Shimura
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Abstract
In a piezoelectric ceramic composition including potassium sodium niobate, a transition temperature at which a phase transition between an orthorhombic crystal structure and a tetragonal crystal structure occurs lies in a temperature range of −20° C. or higher and 60° C. or lower. In the piezoelectric ceramic composition, αt/αo is 0.72 or more, where αo represents a coefficient of linear expansion determined when a crystal structure is orthorhombic in the temperature range, and αt represents a coefficient of linear expansion determined when a crystal structure is tetragonal in the temperature range.
Claims12
A piezoelectric ceramic composition comprising:
- potassium sodium niobate,
- wherein a transition temperature at which a phase transition between an orthorhombic crystal structure and a tetragonal crystal structure occurs lies in a temperature range of −20° C. or higher and 60° C. or lower, and
- αt/αo is 0.72 or more,
- where αo represents a coefficient of linear expansion determined when a crystal structure is orthorhombic in the temperature range, and αt represents a coefficient of linear expansion determined when a crystal structure is tetragonal in the temperature range.
A piezoelectric actuator comprising:
- a piezoelectric ceramic based on potassium sodium niobate,
- wherein the piezoelectric ceramic has, in a temperature range in which a voltage is applied to the piezoelectric ceramic, a transition temperature at which a phase transition between an orthorhombic crystal structure and a tetragonal crystal structure occurs lies in a temperature range of −20° C. or higher and 60° C. or lower, and
- αt/αo is 0.72 or more,
- where αo represents a coefficient of linear expansion determined when a crystal structure is orthorhombic in the temperature range, and αt represents a coefficient of linear expansion determined when a crystal structure is tetragonal in the temperature range, and
- the piezoelectric ceramic comprising potassium sodium niobate.
Dependencies are inferred from the claim text.