Low-temperature sintered PMnS–PZT multilayer-ceramic for nano-step piezomotor application

Multilayer piezoceramic featured with low driving voltage and large generation force is a basic core component of piezoelectric motors. It has been found that Pb(Mn_1/3Sb_2/3)O₃–Pb(Zr,Ti)O₃ (PMnS–PZT) piezoceramic is a powerful system as it simultaneously exhibits a large piezoelectric coefficient (d) and a high mechanical quality factor (Q). However, a quite high sintering temperature (> 1200 ℃) is required, which limits the low-temperature co-firing preparation of the PMnS–PZT multilayer ceramic. In this work, we report a high-performance PMnS–PZT multilayer ceramic using Li₂CO₃ as a sintering aid and a linear piezoelectric motor based on the multilayer ceramic. The investigations show that a 0.4 wt% Li₂CO₃-modified PMnS–PZT ceramic sintered at 980 ℃ exhibits excellent ferroelectric, piezoelectric and electromechanical coupling properties. Furthermore, a 12-layer structured linear piezomotor was fabricated based on the Li₂CO₃-modified PMnS–PZT multilayer ceramic (with Ag/Pd internal electrodes), which shows a superhigh unit volume driving force in comparison with the previously reported piezoelectric motors and a 50 nm step resolution. The obtained results indicated that Li₂CO₃-modified PMnS–PZT ceramic and its multilayer structure have great potential for high-power device applications.