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Full-Text Articles in Physics
Imaging Mechanism Of Piezoresponse Force Microscopy In Capacitor Structures, Sergei V. Kalinin, Brian J. Rodriguez, Seung-Hyun Kim, Suk-Kyoung Hong, Alexei Gruverman, Eugene E. Eliseev
Imaging Mechanism Of Piezoresponse Force Microscopy In Capacitor Structures, Sergei V. Kalinin, Brian J. Rodriguez, Seung-Hyun Kim, Suk-Kyoung Hong, Alexei Gruverman, Eugene E. Eliseev
Alexei Gruverman Publications
The image formation mechanism in piezoresponse force microscopy (PFM) of capacitor structures is analyzed. We demonstrate that the spatial resolution is a bilinear function of film and top electrode thicknesses and derive the corresponding analytical expressions. For many perovskites, the opposite contributions of d31 and d33 components can result in anomalous domain wall profiles. This analysis establishes the applicability limits of PFM for polarization dynamics studies in capacitors and applies them to other structural probes, including focused x-ray studies of capacitor structures.
Piezoresponse Force Microscopy Studies Of Switching Behavior Of Ferroelectric Capacitors On A 100-Ns Time Scale, Alexei Gruverman, D. Wu, J. F. Scott
Piezoresponse Force Microscopy Studies Of Switching Behavior Of Ferroelectric Capacitors On A 100-Ns Time Scale, Alexei Gruverman, D. Wu, J. F. Scott
Alexei Gruverman Publications
Piezoresponse force microscopy is a powerful technique for nm-scale studies but is usually limited by response time. In this Letter, we report the first direct studies of ferroelectric capacitor switching on a submicrosecond time scale. Simultaneous domain imaging and sub-µs transient current measurements establish a direct relationship between polarization P(t) and domain kinetics. Switching times scale with capacitor size over an order of magnitude. Small capacitors, where polarization reversal is dominated by domain wall motion, switch faster at high fields but more slowly at low fields while larger capacitors do the reverse.
Experimental Evidence Of Strain Relaxed Domain Structure In (100)/(001)-Oriented Epitaxial Lead Titanate Thick Films Grown By Metal Organic Chemical Vapor Deposition, Hiroshi Nakaki, Yong Kwan Kim, Shintaro Yokoyama, Rikyu Ikariyama, Hiroshi Funakubo, S. K. Streiffer, Ken Nishida, Keisuke Saito, Alexei Gruverman
Experimental Evidence Of Strain Relaxed Domain Structure In (100)/(001)-Oriented Epitaxial Lead Titanate Thick Films Grown By Metal Organic Chemical Vapor Deposition, Hiroshi Nakaki, Yong Kwan Kim, Shintaro Yokoyama, Rikyu Ikariyama, Hiroshi Funakubo, S. K. Streiffer, Ken Nishida, Keisuke Saito, Alexei Gruverman
Alexei Gruverman Publications
Epitaxial (100)/(001)-oriented PbTiO3 films with thickness of 2.8 μm were grown on Nb-doped (100) SrTiO3 substrates by pulsed metal organic chemical vapor deposition. Complex domain structures consisting of c-domains (c1) and three types of a-domains (a1, a2, and a3) were observed by piezoresponse force microscopy in conjunction with high-resolution x-ray diffraction analysis. The obtained results suggest that (a2/a3) and (a1/c1) domain configurations represent mostly strain-relaxed structures. This conclusion is in good agreement with theoretical predictions made for thick films [Phys. State., Solidi 37, 329 (1976)].
Peculiar Effect Of Mechanical Stress On Polarization Stability In Micrometer-Scale Ferroelectric Capacitors, Alexei Gruverman, J. S. Cross, W.S. Oates
Peculiar Effect Of Mechanical Stress On Polarization Stability In Micrometer-Scale Ferroelectric Capacitors, Alexei Gruverman, J. S. Cross, W.S. Oates
Alexei Gruverman Publications
Piezoresponse force microscopy (PFM) has been used to study the polarization stability in micrometer size Pb(Zr,Ti)O3 capacitors. It is shown that the top electrode thickness has a profound effect on the equilibrium polarization state of poled capacitors triggering spontaneous polarization backswitching in the absence of an applied electric field and leading to the formation of an abnormal domain pattern. PFM examination of poled capacitors with thick (250 nm) top electrodes reveals domain patterns with the central regions always oriented in the direction opposite to the applied field. It is suggested that the driving force behind the observed effect is …
Nanodomain Faceting In Ferroelectrics, J. F. Scott, Alexei Gruverman, D. Wu, M. Alexe
Nanodomain Faceting In Ferroelectrics, J. F. Scott, Alexei Gruverman, D. Wu, M. Alexe
Alexei Gruverman Publications
We show that after long times (24 h), individual circular domains in 50 nm thick [0 0 1] epitaxial films of ferroelectric lead zirconate titanate (PZT) develop facets due to the crystalline anisotropy, e.g. along [1 0 0] directions. This appears to be a creep process (Tybell et al. 2002 Phys. Rev. Lett. 89 097601; Paruch et al. 2006 J. Appl. Phys. 100 051608) and was first seen in a nanoarray of 180° domains (Ganpule et al. 2002 Phys. Rev. B 65 014101). The effect is independent of polarity and thus rules out any electronic dependence on different work functions …
Vortex Ferroelectric Domains, Alexei Gruverman, D. Wu, H.-J. Fan, I. Vrejoiu, M. Alexe, R. J. Harrison, J. F. Scott
Vortex Ferroelectric Domains, Alexei Gruverman, D. Wu, H.-J. Fan, I. Vrejoiu, M. Alexe, R. J. Harrison, J. F. Scott
Alexei Gruverman Publications
We show experimental switching data on microscale capacitors of lead–zirconate–titanate (PZT), which reveal time-resolved domain behavior during switching on a 100 ns scale. For small circular capacitors, an unswitched domain remains in the center while complete switching is observed in square capacitors. The observed effect is attributed to the formation of a vortex domain during polarization switching in small circular capacitors. This dynamical behavior is modeled using the Landau–Lifshitz–Gilbert equations and found to be in agreement with experiment. This simulation implies rotational motion of polarization in the xy plane, a Heisenberg-like result supported by the recent model of Naumov and …
Abnormal Domain Switching In Pb(Zr, Ti)O3 Thin Film Capacitors, Aiying Wu, Paula Vilarinho, Dong Wu, Alexei Gruverman
Abnormal Domain Switching In Pb(Zr, Ti)O3 Thin Film Capacitors, Aiying Wu, Paula Vilarinho, Dong Wu, Alexei Gruverman
Alexei Gruverman Publications
Observation of abnormal (against the applied electric field) domain switching in Pb(ZrxTi1−x)O3 films by piezoresponse force microscopy is reported. In some grains polarization orients opposite to the external field in the presence of the applied field, while the rest of the film volume switches in a normal way. This effect is observed in thin film capacitors which excludes charge injection effect and spontaneous backswitching due the built-in field, which is the possible reason for this behavior. The abnormal switching behavior is attributed to the charge compensation effect at the boundaries of the grains with rhombohedral …