Unlocking the Secrets of Dynamic Piezoelectricity in Ferroelectric Hafnia

Hafnium oxide thin films are a fascinating class of materials with robust ferroelectric properties in the nanometer range. While the ferroelectric behavior is extensively studied, results on piezoelectric effects have so far remained mysterious. A new study now shows that the piezoelectricity in ferroelectric Hf0.5Zr0.5O2 thin films can be dynamically changed by electric field cycling. Another ground-breaking result is a possible occurrence of an intrinsic non-piezoelectric ferroelectric compound. These unconventional features in hafnia offer new options for use in microelectronics and information technology.