Piezoelectric and Ferroelectric Materials Research

Piezoelectric Materials

Piezoelectrics are materials that lack a center of symmetry to the crystallographic unit cell. Therefore, when a stress is applied to the crystal, the ions displace and cause separation of positive and negative charge centers. This enables the material to convert between mechanical energy (stress) and electrical energy (charge), in either direction. Our team has investigated aluminum nitride-based alloys for increased piezoelectric performance. We are also studying ferroelectric response in (Al,Sc)N with high scandium content and related materials.

For more information, see the following publications:

Review of High-Throughput Approaches to Search for Piezoelectric Nitrides, Journal of Vacuum Science & Technology (2019)

Implications of Heterostructural Alloying for Enhanced Piezoelectric Performance of (Al, Sc) N, Physical Review Materials (2018). 

Ferroelectric Materials

Ferroelectrics are a subset of piezoelectrics in that they also possess a spontaneous polarization (remains without applied field) in the unit cell, which can be reoriented by application of an electric field. These are experimentally determined. In addition to (Al,Sc)N ferroelectric alloys, our team also focuses on the discovery and benchmark of nitride perovskites. Oxide pervoskites are well known for possessing useful piezoelectric and ferroelectric properties, but very little is known about nitride perovskites.

For more information, see the following publications:

Reduced Coercive Field in Epitaxial Thin Film of Ferroelectric Wurtzite Al0.7Sc0.3N, Applied Physics Letters (2021)

Understanding Reproducibility of Sputter Deposited Metastable Ferroelectric Wurtzite Al0.6Sc0.4N Films using In‐situ Optical Emission Spectrometryphysica status solidi – Rapid Research Letters (2021)

Synthesis of Polar LaWN3—the First Nitride Perovskite, arXiv (2020)

Synthesis of Lanthanum Tungsten Oxynitride Perovskite Thin Films, Advanced Electronic Materials (2019).