Transparency discovered in crystals with ultrahigh piezoelectricityUse of an AC rather than a DC ele

Transparency discovered in crystals with ultrahigh piezoelectricity

Use of an AC rather than a DC electric field can improve the piezoelectric response of a crystal. Now, an international team of researchers say that cycles of AC fields also make the internal crystal domains in some materials bigger and the crystal transparent.

“There have been reports that the use of AC fields could significantly improve the piezoelectric responses — for example by 20% to 40% — over DC fields and the improvements have always been attributed to the smaller internal ferroelectric domain sizes that resulted from the cycles of AC fields,” said Long-Qing Chen, Hamer Professor of Materials Science and Engineering, professor of engineering science and mechanics, and professor of mathematics at Penn State. “About three years ago, Dr. Fei Li, then a research associate at the Materials Research Institute at Penn State, largely confirmed the improvement of piezoelectric performances from application of AC fields. However, it was not clear at all how the internal ferroelectric domains evolved during AC cycles.

According to researchers, the work “presents a paradigm to achieve an unprecedented combination of properties and functionalities through ferroelectric domain engineering, and the new transparent ferroelectric crystals reported here are expected to open up a wide range of hybrid device applications, such as medical imaging, self-energy-harvesting touch screens and invisible robotic devices.”

Learn more about this research at Penn State News!