S-cera Co., Ltd.

Sang Koo Kwon

Kang Heon Hur

Dong Hwan Seo

Jong Kuk Hong

Piezoelectric ceramic composition and piezoelectric ceramic device using the same

Disclosed is a piezoelectric ceramic composition comprising a PZT piezoelectric composition, a B-site of which is substituted with a certain material, and chromium oxide, and a piezoelectric device using the piezoelectric ceramic composition. The piezoelectric ceramic composition has good heat resistance and frequency stability, and reduces a leakage current. There is provided the piezoelectric ceramic composition comprising a main component expressed by Pb&lsqb;(Co W ) Ti Zr &rsqb;O (wherein, 0.001&lE;x&lE;0.04, and 0.35 &lE;y&lE;0.55), Cr O in an amount of 0.01 to 2 wt %, MnO in an amount of 0.1 to 0.5 wt %, and an additive in an amount of 0.01 to 2.0 wt %, based on the total weight of the piezoelectric ceramic composition, in which the additive is selected from the group consisting of CoO, MgO, ZnO, Al O , Fe O , Sb O , SnO , CeO , Nb O , V O and WO , and mixtures thereof. The piezoelectric ceramic composition satisfies piezoelectric properties such as kp and Qm needed for a piezoelectric material, and is 320&deg; C. or higher in phase transition temperature, &plusmn;30 ppm/&deg; C. in TCF, and 0.1% or less in oscillation frequency change after reflow; and the piezoelectric ceramic composition also has good piezoelectric properties such that the leakage current is reduced.

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Suwon, South Korea

Sang Koo Kwon