Piezoelectrics and Ferroelectrics
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 .
Comparison of the direct and converse piezoelectric effect.
Ferroelectic Materials
Ferroelectrics are a subset of piezoelectrics in that they also possess a spontaneous polarization (remains without applied feild) in the unit cell which can be reoriented by application of an electric field. These are experiementally determined.
Ferroelectric polarization loops from wurtzite AlScN thin films on substrates
Reviews
Review of high-throughput approaches to search for piezoelectric nitrides
Talley, K. R., Sherbondy, R., Zakutayev, A., & Brennecka, G. L.
Journal of Vacuum Science & Technology A 37, 060803 (2019)
(Al,Sc)N Piezoelectrics
Our team has investigated AlN based alloys for increased piezoelectric perormance.
Implications of heterostructural alloying for enhanced piezoelectric performance of (Al, Sc) N
Talley, K.R., Millican, S.L., Mangum, J., Siol, S., Musgrave, C.B., Gorman, B., Holder, A.M., Zakutayev, A. and Brennecka, G.L., .
Physical Review Materials, 2 063802 (2018)
Enhanced piezoelectric response of AlN via CrN alloying.
Manna, S., Talley, K.R., Gorai, P., Mangum, J., Zakutayev, A., Brennecka, G.L., Stevanović, V. and Ciobanu, C.V.
Physical Review Applied, 9 034026 (2018)
Wu, D., Chen, Y., Manna, S., Talley, K., Zakutayev, A., Brennecka, G., Ciobanu, C.V., Constantine, P. and Packard, C.E.,
IEEE transactions on ultrasonics, ferroelectrics, and frequency control 65, 2167 (2018)
(Al,Sc)N Ferroelectrics
We are also studying ferroelectric response in (Al,Sc)N with high Sc content and related materials
Reduced Coercive Field in Epitaxial Thin Film of Ferroelectric Wurtzite Al0.7Sc0.3N.
Yazawa, K., Drury, D., Zakutayev, A. and Brennecka, G.L.
arXiv:2101.06612 (2021)
Drury, D., Yazawa, K., Mis, A., Talley, K., Zakutayev, A. and Brennecka, G.L.,
arXiv:2101.08755 (2021)
Nitride Perovskites
One focus of our group is the discovery and benchmark of nitride perovskites. Pervoskites are well know for possessing useful piezoelectric and ferroelectric properties.
Synthesis of ferroelectric LaWN3--the first nitride perovskite.
Talley, K.R., Perkins, C.L., Diercks, D.R., Brennecka, G.L. and Zakutayev, A
arXiv:2001.00633 (2020)
Synthesis of Lanthanum Tungsten Oxynitride Perovskite Thin Films
Talley, K.R., Mangum, J., Perkins, C.L., Woods‐Robinson, R., Mehta, A., Gorman, B.P., Brennecka, G.L. and Zakutayev, A.,
Advanced Electronic Materials 5 1900214 (2019)
This research focus is in collaboration with Prof. Geoff Brennecka's at Colorado School of Mines.
Contacts
Andiy Zakutayev
Geoff Brennecka