Lead-Free Piezoceramics: From Local Structure to Application
Jürgen Rödel, Technische Universität Darmstadt, Germany
In the past two decades, the environmental toxicity imposed by the use and disposal of lead-based piezoelectrics led to strong research efforts. This can be traced back to the EU legislation, attempting to restrict lead in electroceramics and a seminal paper by the Toyota group in 2004.
It is now apparent that there is no single compound which is able to replace the prototypical piezoceramic, lead-zirconate-titanate (PZT) alone. I will review the current state-of-the-art, with respect to legislation, scientific achievements, and capabilities of industry and academia by highlighting the following topics:
- Current legislative and regulatory issues
- Scientific problems and solutions encountered when developing lead-free piezoceramics
- Salient examples where lead-free piezoceramics are better than PZT
- Examples from industry, where the first products are ready to be marketed
My prediction is that PZT will be the solution for the majority of applications for the next 10 years, but there will be devices based on lead-free piezoceramics, entering the market in 2-6 years.