Ferroelectrics

• Our work has focused on relaxor ferroelectric oxides - systems that exhibit a diffuse frequency dependent transition in their relative permittivity- as well normal ferroelectric and piezoelectric materials.  These materials have a broad range of applications ranging from capacitors, ultrasonic medical imaging, to piezoelectric transducers.

• We are investigating how the character of the ferroelectric transition is affected by alterations in bulk chemistry and cation order.

• For the so-called PMN (lead magnesium niobate) family of relaxors we have  identified new models for the cation order that permit tailoring of the properties via new processing schemes.  This work has been utilized by several groups in the first principles modeling of the structure, stability, and properties of piezoelectric systems.

• We also interact with the "Center for Piezoelectrics by Design", a first principles theory group focused on predicting and understanding ferroelectric and piezoelectric materials.  Our interactions with theorists interested in pre-predicting new chemistries with potentially enhanced responses has led to the identification of several new perovskite chemistries.

• This work has been funded by the National Science Foundation and by the Office of Naval Research.