Single ferroelectric domain nucleation and growth monitored by high speed piezoforce microscopy

Abstract

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.

High-Speed Piezoresponse Force Microscopy and Machine Learning Approaches for Dynamic Domain Growth in Ferroelectric Materials

“…The processes of domain evolution can be clearly seen in Figure a. Different from the previous studies about dynamic domain evolution using AC combined with DC bias, − only a small AC bias between the tip and the sample is employed in this study. Without the DC bias, the electrostatic effect can be significantly reduced, and the image contrast can be mainly ascribed to the pure domain evolution effect.…”

“…HSPFM can acquire a 256 × 256 pixels image in a few seconds, which allows tracking the dynamic processes of the domain growth or switching by repetitively scanning the same region. Successive HSPFM image frames constitute a time-dependent dataset, which records the progressive domain behavior. , For one frame in the HSPFM experiments, the output dataset has multiple channels, which contain a variety of parameters describing the oscillation of the probe, as well as the spatial information. The local structure and electromechanical response can be reflected on the oscillating signals, including height, amplitude, phase, resonance frequency, and quality factor.…”

Correlation between nanoscale and nanosecond resolved ferroelectric domain dynamics and local mechanical compliance

“…We have separately proven that domain nucleation times and their eventual linear growth rates are uncorrelated, 13 and as noted elsewhere they are exponentially related to the applied voltage. 11,14 Finally, even though on average the domain radii expand smoothly, locally the domain wall velocities and directions clearly vary deterministically with position (e.g., Figure 1). Such directionality for domain growth has separately been correlated to particular crystal directions.…”

“…Polarization switching has received particular attention with the development and widespread use of piezo force microscopy (PFM) 1 , allowing spatially and temporally resolved dynamics investigations of domain switching, growth, or relaxation 2-7 which lately have leveraged pulsing or pump:probe schemes 8,9 and/or high speed scanning capabilities 10,11 that even allow polarization mapping during actual switching. [12][13][14] This paper extends such switching dynamics studies into a new area: investigating nascent nucleation and growth dynamics along with their correlation to local mechanical properties.…”

Nanoscale insight into the statics and dynamics of polarization behavior in thin film ferroelectric capacitors

“…A high-speed version of PFM (HSPFM) has been developed by Huey's group to allow image acquisition in several seconds effectively increasing time resolution by two orders of magnitude over the conventional PFM imaging [15,16]. This approach, which involves high-speed scanning of a bare ferroelectric surface with a tip under a superposition of a switching and imaging bias, allows effective studies of the dynamics of domain nucleation and growth but requires relatively smooth surfaces.…”