Back to results
US 7,608,215 B2Granted
Method of manufacturing a piezoelectric ceramic composition
AssigneeTDK Corporation
InventorsTomohisa Azuma, Masakazu Hirose
Life of this patent
Estimating the term…
Abstract
There are provided steps of polarizing a ceramic composition including a perovskite compound containing Pb, Zr, Ti and Mn as main components and a heat treatment step for keeping the polarized ceramic composition within a temperature range lower than Tc (Tc denoting the Curie temperature of the ceramic composition) for 1 to 100 minutes.
Claims5
A manufacturing method for a piezoelectric ceramic composition comprising steps of:
- polarizing a ceramic composition comprising a perovskite compound containing Pb, Zr, Ti, Mn and Nb;
- and
- heat-treating said polarized ceramic composition within a temperature range higher than 0.80 Tc and lower than Tc (Tc denoting the Curie temperature of said ceramic composition) for 1 to 40 minutes,
- wherein the Curie temperature Tc of said ceramic composition is 340° C. or higher;
- wherein said ceramic composition is represented by a formula, Pbα[(Mn1/3Nb2/3)xTiyZrz]O3, in which α, x , y and z fall within the ranges of 0.95≦α≦1.02, 0.02≦x≦0.15, 0.48≦y≦0.62, and 0.30≦z≦0.42, respectively;
- and wherein said ceramic composition comprises as an additive Mn in 0.65 wt % or less (not inclusive of 0) in terms of MnCO3 and/or Cr in 0.65 wt % or less (not inclusive of 0) in terms of Cr2O3.
3 more elements
Dependencies are inferred from the claim text.