CTS Corporation
LEAD-FREE KNN-BASED PIEZOELECTRIC CERAMIC MATERIAL WITH TEXTURING, AND METHOD OF MAKING THE SAME

Abstract:

A lead-free KNN-based piezoelectric material represented by the composition formula (K.sub.aNa.sub.bLi.sub.c)(Nb.sub.dTa.sub.eSb.sub.f)O.sub.g, where 0.4.ltoreq.a.ltoreq.0.5, 0.5.ltoreq.b.ltoreq.0.6, 0.01.ltoreq.c.ltoreq.0.1, 0.5.ltoreq.d.ltoreq.1.0, 0.05.ltoreq.e.ltoreq.0.15, 0.01.ltoreq.f.ltoreq.0.09, 1.ltoreq.g.ltoreq.3. In one embodiment, the lead-free KNN-based piezoelectric material has a d.sub.33>300 pm/V and a T.sub.curie>250.degree. C. In one embodiment, the d.sub.33 and T.sub.curie of the lead-free textured KNN-based piezoelectric material can be adjusted by creating phase boundaries of (i) orthorhombic to tetragonal (O-T), (ii) rhombohedral to orthorhombic (R-O), and (iii) orthorhombic to tetragonal (O-T). In one embodiment, the lead-free KNN-based piezoelectric material is textured with NaNbO.sub.3 or Ba.sub.2NaNb.sub.5O.sub.15 seeds which are platelet or acicular shaped. In one embodiment, the amount, orientation, or particle size distribution of the NaNbO.sub.3 or Ba.sub.2NaNb.sub.5O.sub.15 texturing seeds in the lead-free textured KNN-based piezoelectric material can be altered.