While commonly used piezoelectric materials contain lead, non-hazardous, high-performancepiezoelectrics are yet to be discovered. Charged domain walls in ferroelectrics are consideredinactive with regards to the piezoelectric response and, therefore, are largely ignored in thissearch. Here we demonstrate a mechanism that leads to a strong enhancement of the dielectricand piezoelectric properties in ferroelectrics with increasing density of charged domain walls.We show that an incomplete compensation of bound polarization charge at these walls createsa stable built-in depolarizing field across each domain leading to increased electromechanicalresponse. our model clarifies a long-standing unexplained effect of domain wall densityon macroscopic properties of domain-engineered ferroelectrics. We show that non-toxicferroelectrics like BaTio3with dense patterns of charged domain walls are expected to havestrongly enhanced piezoelectric properties, thus suggesting a new route to high-performance,lead-free ferroelectrics.
展开▼
