High Performance Lead-Free Piezoelectric Materials

Conventional piezoelectric materials of the Pb(Zr,Ti)O3 family are widely used in electronic components such as acceleration sensors, piezoelectric actuators, and knock sensors. However, these materials contain the harmful element lead; therefore, there is a strong demand to develop lead-free piezoelectric materials. To answer this demand, we have developed high performance lead-free piezoelectric ceramics that are environmentally friendly. The developed material has a new composition and a very unique microstructure with crystal-axis orientated and aligned block-shaped grains, which is produced using the newly developed texture-orientation process, the reactive templated grain growth method, and by design of the phase boundary in the crystal structure. Moreover, the developed material has a piezoelectric constant that is two times larger ^*1 than that of conventional lead-free piezoelectric materials. In the future, it is expected that lead-free piezoelectric devices such as high sensitivity piezoelectric sensors, knock sensors, and piezoelectric ultrasonic motors can be realized using this new material. The results were published in the journal Nature in 2004.

• *1 Piezoelectric Property : 416pC/N