An atomic force microscopy (AFM) based technique is described for mapping piezoactuation with nanoscale resolution in less than a second per complete image frame. “High speed piezo force microscopy” (HSPFM) achieves this >100× increase in acquisition rates by coupling a commercial AFM with concepts of acoustics. This allows previously inaccessible dynamic studies, including measuring ferroelectric domain nucleation and growth during in situ poling. Hundreds of consecutive images are analyzed with 49 μs temporal resolution per pixel per frame, revealing 32 nucleation sites/μm2 with 36 μm/s average domain velocities. HSPFM images acquired in as fast as 1/10th s are also presented.

A high speed variation of Scanning Probe Microscopy with continuous image rates on the order of 1 frame per second is applied to investigate the nucleation and growth of individual ferroelectric domains. Movies of consecutive images directly identify nascent domains and their nucleation times, while tracking their development with time and voltage reveals linear domain growth at lateral velocities near 1 mm/s, even faster for nascent domains. Nanoscale maps of nucleation times and growth velocities indicate that domain nucleation and growth are uncorrelated, varying extensively with position. Domain switching dynamics do strongly couple to film defects; for instance, grain boundaries can profoundly pin domain walls, and polarization reversal kinetics are influenced by strain fields near microcracks or in asymmetric specimens. The influence of the onset of switching fatigue is observed as well. These results highlight the importance of updating classical interpretations of ferroelectric switching for truly rigorous models of polarization dynamics. Coupling high speed SPM imaging with in situ activation by voltage or other parameters therefore provides an important methodology to research dynamic surface properties with nanoscale resolution, extendable to a range of materials such as photovoltaics,

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The dynamics of ferroelectric domain switching are directly mapped in a PbZr0.2Ti0.8O3 thin film using piezoresponse force microscopy. Employing the rastering tip as a poling electrode to locally apply a fixed bias near the coercive field, while simultaneously monitoring the evolving domain pattern during continuous imaging, the effectively independent switching dynamics for numerous domains are directly investigated. While areal poling follows the anticipated S‐curve, this is shown to be the collective outcome of linear terminal radial growth for an ensemble of independently nucleating domains. By repeating such spatially resolved measurements in the same region, but with progressively greater fields, nucleation sites and growth patterns are shown to clearly repeat. This reveals apparent defects which comparatively promote switching, and nucleation times and growth rates that accelerate exponentially. After analyzing and mapping the ratio of activation energies for nucleation to growth, a high density of nucleation sites can possibly be activated with higher poling fields—even if only at the start of a poling process—enabling faster and more efficient switching to be engineered as directly demonstrated.

The local dynamics of ferroelectric domain polarization are uniquely investigated with sub-20-nm resolved maps of switching times, growth velocities, and growth directions. This is achieved by analyzing movies of hundreds of consecutive high speed piezo force microscopy images, which record domain switching dynamics through repeatedly alternating between high speed domain imaging and the application of 20-nanosecond voltage pulses. Recurrent switching patterns are revealed, and domain wall velocities for nascent domains are uniquely reported to be up to four times faster than for mature domains with radii greater than approximately 100 nm. Switching times, speeds, and directions are also shown to correlate with local mechanical compliance, with domains preferentially nucleating and growing in compliant sample regions while clearly shunting around locations with higher stiffness. This deterministic switching behavior strongly supports a defect-mediated energy landscape which controls polarization reversal, and that can therefore be predicted, modeled, and even manipulated through composition, processing, and geometry. Such results have important implications for the practical performance of ferroelectric devices by enabling guided optimization of switching times and feature densities, while the methods employed provide a new means to investigate and correlate dynamic functionality with mechanical properties at the nanoscale.

Evidence for forward domain growth being rate-limiting step in polarization switching in 〈111〉 -oriented-Pb ( Zr 0.45 Ti 0.55 ) O 3 thin-film capacitors High resolution study of domain nucleation and growth during polarization switching in Pb(Zr,Ti)O 3 ferroelectric thin film capacitors High speed piezoforce microscopy ͑HSPFM͒ is a versatile technique for directly monitoring ferroelectric domain switching with nanoscale resolution. For a single region in a PbZr 0.2 Ti 0.8 O 3 thin film, HSPFM movies are presented at two distinct poling potentials, collectively acquired in less than the time necessary for just a single conventional PFM image. The number of nucleation sites resolved per area is greater for the stronger switching field, while the switching pattern is visibly similar. Focusing on a single domain site, nucleation clearly occurs much more rapidly for the stronger field. Domain growth rates are also quantified for this individual feature and found to increase by a factor of 2 when the dc poling potential is adjusted from negative 1.7 to negative 1.9 V.

A chemical synthesis method is presented for the fabrication of high-definition segmented metal-oxide-metal (MOM) nanowires in two different ferroelectric oxide systems: Au-BaTiO(3)-Au and Au-PbTiO(3)-Au. This method entails electrodeposition of segmented nanowires of Au-TiO(2)-Au inside anodic aluminum oxide (AAO) templates, followed by topotactic hydrothermal conversion of the TiO(2) segments into BaTiO(3) or PbTiO(3) segments. Two-terminal devices from individual MOM nanowires are fabricated, and their ferroelectric properties are measured directly, without the aid of scanning probe microscopy (SPM) methods. The MOM nanowire architecture provides high-quality end-on electrical contacts to the oxide segments, and allows direct measurement of properties of nanoscale volume, strain-free oxide segments. Unusually high ferroelectric responses, for chemically synthesized oxides, in these MOM nanowires are reported, and are attributed to the lack of residual strain in the oxides. The ability to measure directly the active properties of nanoscale volume, strain-free oxides afforded by the MOM nanowire architecture has important implications for fundamental studies of not only ferroelectric nanostructures but also nanostructures in the emerging field of multiferroics.

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