Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Quantitative analysis of ferroelectric domain imaging with piezoresponse force microscopy  [PDF]
T. Jungk,A. Hoffmann,E. Soergel
Physics , 2005, DOI: 10.1063/1.2362984
Abstract: The contrast mechanism for ferroelectric domain imaging via piezoresponse force microscopy (PFM) is investigated. A novel analysis of PFM measurements is presented which takes into account the background caused by the experimental setup. This allows, for the first time, a quantitative, frequency independent analysis of the domain contrast which is in good agreement with the expected values for the piezoelectric deformation of the sample and satisfies the generally required features of PFM imaging.
Consequences of the background in piezoresponse force microscopy on the imaging of ferroelectric domain structures  [PDF]
T. Jungk,A. Hoffmann,E. Soergel
Physics , 2005,
Abstract: The interpretation of ferroelectric domain images obtained with piezoresponse force microscopy (PFM) is discussed. The influences of an inherent experimental background on the domain contrast in PFM images (enhancement, nulling, inversion) as well as on the shape and the location of the domain boundaries are described. We present experimental results to evidence our analysis of the influence of the background on the domain contrast in PFM images.
Etch Damage Evaluation in Integrated Ferroelectric Capacitor Side Wall by Piezoresponse Force Microscopy

WANG Long-Hai,DAI Ying,DENG Zhao,

中国物理快报 , 2008,
Abstract: The etch damage in integrated ferroelectric capacitors side wall fabricated by the typical integrated process (TIP-FeCAP) and the innovated integrated process (IIP-FeCAP) are investigated by piezoresponse force microscopy (PFM). The IIP-FeCAP side wall exhibits fine and clear nanoscale domain images and the same piezoresponse signal as the thin film, and the domains can also be easily switched by an external voltage. In the TIP-FeCAP side wall, owing to the effect of etch damage, the very weak piezoresponse signal and some discrete domains can be observed, and the discrete domains cannot be switched by the applied 9V and -9V dc voltage. The PFM results reflect the etch damage in the integrated ferroelectric capacitors and also suggest that the PFM can be used as an efficacious tools to evaluate the etch damage at nanoscale and spatial variations.
Nanoelectromechanics of Piezoresponse Force Microscopy  [PDF]
Sergei V. Kalinin,Edgar Karapetian,Mark Kachanov
Physics , 2004, DOI: 10.1103/PhysRevB.70.184101
Abstract: To achieve quantitative interpretation of Piezoresponse Force Microscopy (PFM), including resolution limits, tip bias- and strain-induced phenomena and spectroscopy, analytical representations for tip-induced electroelastic fields inside the material are derived for the cases of weak and strong indentation. In the weak indentation case, electrostatic field distribution is calculated using image charge model. In the strong indentation case, the solution of the coupled electroelastic problem for piezoelectric indentation is used to obtain the electric field and strain distribution in the ferroelectric material. This establishes a complete continuum mechanics description of the PFM contact mechanics and imaging mechanism. The electroelastic field distribution allows signal generation volume in PFM to be determined. These rigorous solutions are compared with the electrostatic point charge and sphere-plane models, and the applicability limits for asymptotic point charge and point force models are established. The implications of these results for ferroelectric polarization switching processes are analyzed.
Dynamic Behavior in Piezoresponse Force Microscopy  [PDF]
Stephen Jesse,Arthur P. Baddorf,Sergei V. Kalinin
Physics , 2005, DOI: 10.1088/0957-4484/17/6/014
Abstract: Frequency dependent dynamic behavior in Piezoresponse Force Microscopy (PFM) implemented on a beam-deflection atomic force microscope (AFM) is analyzed using a combination of modeling and experimental measurements. The PFM signal comprises contributions from local electrostatic forces acting on the tip, distributed forces acting on the cantilever, and three components of the electromechanical response vector. These interactions result in the bending and torsion of the cantilever, detected as vertical and lateral PFM signals. The relative magnitudes of these contributions depend on geometric parameters of the system, the stiffness and frictional forces of tip-surface junction, and operation frequencies. The dynamic signal formation mechanism in PFM is analyzed and conditions for optimal PFM imaging are formulated. The experimental approach for probing cantilever dynamics using frequency-bias spectroscopy and deconvolution of electromechanical and electrostatic contrast is implemented.
Depth Resolution of Piezoresponse Force Microscopy  [PDF]
Florian Johann,Yongjun J. Ying,Tobias Jungk,Akos Hoffmann,Collin L. Sones,Robert W. Eason,Sakellaris Mailis,Elisabeth Soergel
Physics , 2009, DOI: 10.1063/1.3126490
Abstract: Given that a ferroelectric domain is generally a three dimensional entity, the determination of its area as well as its depth is mandatory for full characterization. Piezoresponse force microscopy (PFM) is known for its ability to map the lateral dimensions of ferroelectric domains with high accuracy. However, no depth profile information has been readily available so far. Here, we have used ferroelectric domains of known depth profile to determine the dependence of the PFM response on the depth of the domain, and thus effectively the depth resolution of PFM detection.
Materials Contrast in Piezoresponse Force Microscopy  [PDF]
Sergei V. Kalinin,Eugene A. Eliseev,Anna N. Morozovska
Physics , 2006, DOI: 10.1063/1.2206992
Abstract: Piezoresponse Force Microscopy contrast in transversally isotropic material corresponding to the case of c+ - c- domains in tetragonal ferroelectrics is analyzed using Green's function theory by Felten et al. [J. Appl. Phys. 96, 563 (2004)]. A simplified expression for PFM signal as a linear combination of relevant piezoelectric constant are obtained. This analysis is extended to piezoelectric material of arbitrary symmetry with weak elastic and dielectric anisotropies. This result provides a framework for interpretation of PFM signals for systems with unknown or poorly known local elastic and dielectric properties, including nanocrystalline materials, ferroelectric polymers, and biopolymers.
Influence of the inhomogeneous field at the tip on quantitative piezoresponse force microscopy  [PDF]
T. Jungk,A. Hoffmann,E. Soergel
Physics , 2006, DOI: 10.1007/s00339-006-3768-9
Abstract: Ferroelectric domain imaging with piezoresponse force microscopy (PFM) relies on the converse piezoelectric effect: a voltage applied to the sample leads to mechanical deformations. In case of PFM one electrode is realized by the tip, therefore generating a strongly inhomogeneous electric field distribution inside the sample which reaches values up to $10^8 $V/m directly underneath the apex of the tip. Although often assumed, this high electric field does not lead to an enhancement of the piezoelectric deformation of the sample. On the contrary, internal clamping of the material reduces the observed deformation compared to the theoretically expected value which depends only on the voltage thus being independent of the exact field distribution.
A Decade of Piezoresponse Force Microscopy: Progress, Challenges and Opportunities  [PDF]
Sergei V. Kalinin,Andrei Rar,Stephen Jesse
Physics , 2005,
Abstract: Coupling between electrical and mechanical phenomena is a near-universal characteristic of inorganic and biological systems alike, with examples ranging from ferroelectric perovskites to electromotor proteins in cellular membranes. Understanding electromechanical functionality in materials such as ferroelectric nanocrystals, thin films, relaxor ferroelectrics, and biosystems requires probing these properties on the nanometer level of individual grain, domain, or protein fibril. In the last decade, Piezoresponse Force Microscopy (PFM) was established a powerful tool for nanoscale imaging, spectroscopy, and manipulation of ferroelectric and piezoelectric materials. Here, we present principles and recent advances in PFM, including vector and frequency dependent imaging of piezoelectric materials, briefly review applications for ferroelectric materials, discuss prospects for electromechanical imaging of local crystallographic and molecular orientations and disorder, and summarize future challenges and opportunities for PFM emerging in the second decade since its invention.
Limitations for the determination of piezoelectric constants with piezoresponse force microscopy  [PDF]
T. Jungk,A. Hoffmann.,E. Soergel
Physics , 2007, DOI: 10.1063/1.2827566
Abstract: At first sight piezoresponse force microscopy (PFM) seems an ideal technique for the determination of piezoelectric coefficients (PCs), thus making use of its ultra-high vertical resolution (<0.1 pm/V). Christman et al. \cite{Chr98} first used PFM for this purpose. Their measurements, however, yielded only reasonable results of unsatisfactory accuracy, amongst others caused by an incorrect calibration of the setup. In this contribution a reliable calibration procedure is given followed by a careful analysis of the encounted difficulties determining PCs with PFM. We point out different approaches for their solution and expose why, without an extensive effort, those difficulties can not be circumvented.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.