110 research outputs found
Electric-field-tunable mechanical properties of relaxor ferroelectric single crystal measured by nanoindentation
Electric field dependent mechanical properties of relaxor ferroelectric
material Pb(Mn1/3Nb2/3)O3-PbTiO3 are investigated with the nanoindentation
technique. Giant electric-field-tunable apparent elastic modulus (up to -39%),
hardness (-9% to 20%) and energy dissipation (up to -13%) are reported. Based
on experimental data, a characterization method of electromechanical coupled
nanoindentation is proposed. In this method, an electric field tunable scaling
relationship among elastic modulus, hardness and indentation work for
ferroelectric materials can be determined. In addition, this method can be used
to obtain the electric-field-dependent elastic modulus and hardness, and avoid
the estimate of contact area in the Oliver-Pharr method. Finally, the different
effects on elastic modulus between positive and negative electric fields can be
explained by the flexoelectric effect.Comment: 14 pages, 4 figure
Switching spectroscopic measurement of surface potentials on ferroelectric surfaces via an open-loop Kelvin probe force microscopy method
We report a method for switching spectroscopy Kelvin probe force microscopy (SS-KPFM). The method is established as a counterpart to switching spectroscopy piezoresponse force microscopy (SS-PFM) in Kelvin probe force microscopy. SS-KPFM yields quantitative information about the surface charge state during a local bias-induced polarization switching process, complementary to the electromechanical coupling properties probed via SS-PFM. Typical ferroelectric samples of a Pb-based relaxor single crystal and a BiFeO3 thin film were investigated using both methods. We briefly discuss the observed surfacecharging phenomena and their influence on the associated piezoresponse hysteresis loops.Q.L., Y.L., D.W., and R.L.W. acknowledge the support
of the Australian Research Council (ARC) in the form of
ARC Discovery Grants. Y.L. also acknowledges support
from the ARC Future Fellowships Program
- …