March 2018: Professor Jan Seidel & Dr Pankaj Sharma, "A Critical Morphotropic Phase Boundary"
"Optimizing the electromechanical response in morphotropic BiFeO3"
Exotic physical phenomena and colossal enhancements of functional materials properties emerge often at interfaces or boundaries between competing phases. For example, huge enhancements in the electromechanical and dielectric properties arise in the proximity of so called morphotropic phase boundaries (MPB’s) - highly sought-after interfaces in the field of piezoelectrics and ferroelectrics. In this work, we identify a distinct MPB in the strain-dependent phase diagram for BiFeO3 thin films to achieve exceptionally high piezoelectricity. At such a composite MPB referred to as critical MPB, a colossal electrically recoverable strain approximately 40% higher than the previously reported values is observed. These superior electromechanical couplings in environmentally-friendly lead-free materials hold great potential for their applications in high-frequency actuators and sensors.
Read the full article, as published in Nanotechnology, Volume 29, Issue 20, 20 March 2018, 205703.