Structural and Piezoelectric Properties of (1− x )Pb(Zr 1− y Ti y )O 3 – x Pb(Zn 0.4 Ni 0.6 ) 1/3 Nb 2/3 O 3 Ceramics Near Triple Point

The crystal structure and piezoelectric properties of (1− x )Pb(Zr 1− y Ti y )O 3 ‐ x Pb(Zn 0.4 Ni 0.6 ) 1/3 Nb 2/3 O 3 [(1− x ) PZ 1− y T y ‐ x PZNN] ceramics were investigated. The 0.665 PZ 0.45 T 0.55 ‐0.335 PZNN ceramic has the triple point composition, where the rhombohedral, pseudocubic, and tetragonal structures coexist. Maximum d 33 and k p values of 770 pC/N and 0.69, respectively, were observed from this specimen; it also exhibited a large ε T 33 / ε o value of 3250. Although the maximum d 33 value was obtained from the triple point composition specimen, its g 33 and d 33  ×  g 33 values were relatively small because of its large ε T 33 / ε o value. However, the 0.665 PZ 0.46 T 0.54 ‐0.335 PZNN ceramic, which has a rhombohedral structure, exhibited a large g 33 value of 43 × 10 −3  Vm/N and a d 33  ×  g 33 value of 27 000 × 10 −15  m 2 /N. Therefore, this ceramic is a good candidate for multilayer actuators and piezoelectric energy harvesters.