Tdk Corporation

Yoshiko Gokita

Masahito Furukawa

Shogo Murosawa

Kenji Horino

Kazutaka Suzuki

Yasuharu Miyauchi

Junichi Yamazaki

Masaru Nanao

Tamotsu Ishiyama

Keisuke Itakura

Takumi Satou

Provided is a piezoelectric ceramic with a wider operating temperature range capable of obtaining a larger amount of displacement and being easily sintered, as well as being superior in terms of ultra-low emission, environmental friendliness and ecology. A piezoelectric substratecomprises a composition including a perovskite-type oxide (NaKLiAg)(NbTa)Oand a tungsten bronze-type oxide M(NbTa)O(M is an element of Group 2 in the long form of the periodic table of the elements). The values of x, y and z are preferably within a range of 0.1&#x2266;x&#x2266;0.9, 0&#x2266;y&#x2266;0.2, and 0&#x2266;z&#x2266;0.05, respectively. The content of the tungsten bronze-type oxide is preferably 5.3 mol % or less. Thereby, a higher Curie temperature and a larger amount of displacement can be obtained, and sintering can be more easily carried out.

Piezoelectric porcelain and method for preparation thereof

Provided is a piezoelectric ceramic capable of improving its piezoelectric properties. The piezoelectric ceramic comprises a rhombohedral perovskite structure compound such as (Na Bi )TiO , a tetragonal perovskite structure compound such as BaTiO and (K Bi )TiO and an orthorhombic perovskite structure compound such as NaNbO , KNbO and CaTiO , or the rhombohedral perovskite structure compound, the tetragonal perovskite structure compound and a cubic perovskite structure compound such as SrTiO3. Three kinds of perovskite structure compounds having different crystal structures are comprised, so that the piezoelectric properties can be improved. The three kinds of compounds may perfectly form a solid solution or not.

Piezoelectric ceramic

The piezoelectric ceramic includes oxide represented by (Pb A ) &lsqb;Zn Nb ) (Mn B ) Ti Zr &rsqb;O . A represents at least one element in the group comprising Ca, Sr and Ba. B represents at least one element in the group comprising Nb, Sb and Ta and a, s, w, x, y and z are within a range of 0&lE;a&lE;0.1, 0.9&lE;s<1.0, 0.2&lE;w/x&lE;3.0, 0.1&lE;y&lE;0.5 and 0.2&lE;z&lE;0.6, respectively and w&plus;x&plus;y&plus;z&equals;1. Therefore, the high mechanical strength can be attained easily and reasonably and also the excellent piezoelectric properties are attained without grinding calcined powder or a hot press.

Piezoelectric ceramic and piezoelectric device

Manganese oxide and tantalum oxide are added to a piezoelectric ceramic composition based on lead zinc-niobate titanate zirconate. The composition is suitable for piezo-electric transformers since its mechanical quality factor (Qm) is improved without reducing its electromechanical coupling coefficient (k,), and good high-power properties and high mechanical strength are obtained. In another embodiment, manganese oxide and at least one of antimony oxide and niobium oxide are added to a piezoelectric ceramic composition based on lead zinc-niobate titanate zirconate.

Piezoelectric ceramics and piezoelectric device

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Tokyo, Japan

Yoshiko Gokita