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AssigneeMurata Manufacturing Co., Ltd.
InventorsKiyoshi Hase, Hiroshi Takagi, Akira Ando, Akira Nagai, Yu Tokuda, Koichi Hayashi
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There is provided a piezoelectric ceramic having a small mechanical factor of merit Qm and excellent heat-resisting properties, e.g., a piezoelectric ceramic for filter elements which is compatible with surface mounting and a method of manufacturing the same in a large amount and in a stable manner. There is provided a piezoelectric ceramic which is a composite oxide of at least lead, zirconium and titanium, wherein an oxide of manganese exists in a grain boundary layer in a density higher than that in a crystal grain of the piezoelectric ceramic and a glass phase exists in the grain boundary layer. It is manufactured by depositing a manganese compound and a glass material on the surface of a piezoelectric ceramic comprising a composite oxide of at least lead, zirconium and titanium and by performing thermal processing thereafter to diffuse the deposited substance in a grain boundary portion of the piezoelectric ceramic.
A piezoelectric ceramic comprising a composite oxide of at least lead, zirconium and titanium, in which an oxide of manganese exists in a grain boundary layer at a density higher than that in a crystal grain of said piezoelectric ceramic, and in which a lead glass phase exists in said grain boundary layer.
A manufacturing method for piezoelectric ceramic which comprises heating a piezoelectric ceramic comprising a composite oxide of at least lead, zirconium and titanium having adhered manganese compound and lead glass on a surface thereof at a temperature sufficient to diffuse manganese oxide and glass to grain boundary parts of said piezoelectric ceramic.
Dependencies are inferred from the claim text.