Unconventional piezoelectricity in ferroelectric hafnia

https://phys.org/news/2024-02-unconventional-piezoelectricity-ferroelectric-hafnia.html

"piezoelectricity in ferroelectric Hf0.5Zr0.5O2 (HZO) thin films dynamically changed by electric field cycling... different Hf0 (hafnia) films expand or contract, and ferroelectric polarization can switch against electrical field, in same experimental conditions... HZO capacitor cycling from + to - of piezoelectric d33 coefficient... also, occurrence of an intrinsic non-piezoelectric ferroelectric compound, revolutionizing ferroelectricity... all while polarization remains robust... microelectronics and information technology"

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