Abstract
Relaxor/ferroelectric ceramic/ceramic composites have shown to be promising in generating large electromechanical strain at moderate electric fields. Nonetheless, the mechanisms of polarization and strain coupling between grains of different nature in the composites remain unclear. To rationalize the coupling mechanisms we performed advanced piezoresponse force microscopy (PFM) studies of 0.92BNT-0.06BT-0.02KNN/0.93BNT-0.07BT (ergodic/non-ergodic relaxor) composites. PFM is able to distinguish grains of different phases by characteristic domain patterns. Polarization switching has been probed locally, on a sub-grain scale. k-Means clustering analysis applied to arrays of local hysteresis loops reveals variations of polarization switching characteristics between the ergodic and non-ergodic relaxor grains. We report a different set of switching parameters for grains in the composites as opposed to the pure phase samples. Our results confirm ceramic/ceramic composites to be a viable approach to tailor the piezoelectric properties and optimize the macroscopic electromechanical characteristics.
| Original language | English |
|---|---|
| Pages (from-to) | 2168-2176 |
| Number of pages | 9 |
| Journal | Nanoscale |
| Volume | 8 |
| Issue number | 4 |
| DOIs | |
| State | Published - Jan 28 2016 |
Funding
This work has been supported by the European Commission within FP7 Marie Curie Initial Training Network "Nanomotion" (grant agreement no. 290158). The research was conducted at the Center for Nanophase Materials Sciences, which is sponsored at Oak Ridge National Laboratory by the Scientific User Facilities Division, Proposal Number: CNMS2013-250. DG acknowledges the experimental support of Dr Evgeni Strelcov. CG was supported by the Leibniz program of the Deutsche Forschungsgemeinschaft under Ro 954/22.