PIEZOELECTRIC/ELECTROSTRICTIVE CERAMIC, METHOD FOR PRODUCING PIEZOELECTRIC/ELECTROSTRICTIVE CERAMIC, PIEZOELECTRIC/ELECTROSTRICTIVE ELEMENT, AND METHOD FOR MANUFACTURING PIEZOELECTRIC/ELECTROSTRICTIVE ELEMENT

• Main Authors: TANAKA RITSU, MIYAYAMA MASARU, KOIZUMI TAKAAKI, NOGUCHI YUJI, OZAWA SHUICHI, KASHIWAYA TOSHIKATSU
• Format: Patent
• Language: English
• Published: 13.10.2011
• Subjects: ARTIFICIAL STONE; CEMENTS; CERAMICS; CHEMISTRY; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; CONCRETE; ELECTRICITY; LIME, MAGNESIA; METALLURGY; REFRACTORIES; SLAG; TREATMENT OF NATURAL STONE

PROBLEM TO BE SOLVED: To provide a piezoelectric/electrostrictive ceramic which produces large electric-field induced strain without performing an aging treatment for a long period of time.SOLUTION: In a production method for such a piezoelectric/electrostrictive ceramic, a piezoelectric/electrostrictive ceramic sintered body, in which the ratio of the number of ions at A sites to the number of ions at B sites in a perovskite structure is 0.94-0.99, is subjected to an oxygen heat treatment at a temperature of 600-1,050°C for 2-100 h under an atmosphere with an oxygen partial pressure of 0.05-1.0 atm. Alternatively, the piezoelectric/electrostrictive ceramic is provided with a composition represented by the formula: (BiNaKBa)TiO, wherein w, x, y and z satisfy the following expressions: 0.35≤w≤0.53; 0.30≤x≤0.47; 0.00≤y≤0.12; 0.00≤z≤0.14; and 0.94≤w+x+y+z≤0.99, and at least one of y and z is not 0.