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Showing 1 to 20 of 32 for “"Piezoresponse"”.
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Investigation of Ferroelectric Thin Film Using Piezoresponse Force Microscopy
… earlier work on this topic, resonance enhanced piezoresponse force microscopy was introduced and theoretical models were developed to support quantitative imaging with PFM. The resonant PFM mechanism was thoroughly investigated, and functional materials including tetragonal polycrystalline …
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High Performance Lead--free Piezoelectric Materials
… field in last few decades owing to their giant piezoresponse and convenient application relevant tunability. With increasing environmental concerns, in the last one decade, focus has been shifted towards developing a better understanding of lead-free piezoelectric compositions in order to …
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Kraftmikroskopische Untersuchungen dünner ferroelektrischer Filme
… of scanning force microscopy - specifically Piezoresponse and Kelvin-Probe. The film thickness of the investigated samples ranged between 50nm and 800nm. This experimental work focussed on the following issues: native domain structures, creation of domains by short voltage pulses and …
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Multiferroic BiFeO3 films and nanostructures for hybrid energy harvesters
… force microscopy (AFM). Coupled to the AFM, piezoresponse force microscopy (PFM) and piezoresponse force spectroscopy (PFS) have permitted the imaging of ferroelectric domains and the confirmation of the films’ piezoelectric properties. The first part of the thesis is dedicated to the …
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Electrodeposited Functional Nanowires for Energy Applications
… force microscopy (KPFM) and non--destructive piezoresponse force microscopy (ND-PFM). Both nanoscale and bulk ME measurements have been performed on Ni - P(VDF-TrFE) ME composite (1-1) NWs, nanocomposite (1-3) films and (2-2) laminates. The latter two structures have been fabricated using TAED …
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Interfacial Properties of Graphene and 2D Materials Heterostructures Investigated by Scanning Probe Microscopy
… resonance atomic force microscopy (CR-AFM) and piezoresponse force microscopy (PFM), are applied to study the interfacial mechanical and piezoelectrical properties of graphene and 2D materials heterostructures. For the first time, CR-AFM is demonstrated with the sensitivity to local stiffness …
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Nanostructured ferroelectric materials
… Chapter 2 details the general principles of piezoresponse microscopy (PFM). Chapter 3 highlights the fabrication of arrays of Sb2S3 nanowires with variable diameters using newly developed solventless template-based approach. A detailed account of domain imaging and polarisation switching of …
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Deposition, Characterization, and Fabrication of a Zinc Oxide Piezoelectric Thin Film Microspeaker Using DC Reactive Sputtering
… ZnO were discovered with an Asylum MFP-3D and a piezoresponse force microscopy (PFM) technique called DART-PFM. The ZnO films that were sputtered with 70 watts and an argon to oxygen gas ratio of 2:1 were found to have the highest <em>d<sub>33</sub></em> piezoelectric coefficients. The ZnO sample …
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Nanometer-thick oxide films for pyroelectric energy conversion
… films deposited using pulsed laser deposition. Piezoresponse force microscopy (PFM), an atomic force microscopy (AFM) based technique, measured the electromechanical response while a doped-silicon resistive micro-heater provided local temperature control up to 400 °C. Three techniques …
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Dielectric and pyroelectric susceptibilities of epitaxial ferroelectric thin films
… techniques such as x-ray di ffraction, piezoresponse force microscopy, and electrical measurements. We show that large dielectric and pyroelectric susceptibilities can be obtained in tensile strained PZT thin fi lms due to the displacement of 90° domain walls and thermal expansion …
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Magnetoelectric Oxide Nanocomposite Heterostructures
… by the switching the characteristics of the piezoresponse for the new heterostructure. Second, for the option for candidates thin film materials with a high piezoelectric coefficient, which is a critical factor for ME composite films, I utilized the simple compositional BaSn0.11Ti0.89O3 bulk …
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Orientation dependence of dielectric susceptibilities and switching characteristics in epitaxial ferroelectric thin films
… are subsequently observed in stroboscopic piezoresponse force microscopy. These results have implications for our understanding of ferroelectric switching and offer opportunities to change domain reversal speed. Our work also offers new insights into the microscopic origin of dielectric …
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Multiscale Simulations of Dynamics of Ferroelectric Domains
… are subsequently observed in stroboscopic piezoresponse force microscopy. Finally, we investigate the domain walls in organometal halide perovskites. We find that organometal halide perovskites can form both charged and uncharged domain walls, due to the flexible orientational order of the …
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New modalities for strain engineering of lead-free perovskite ferroelectric thin films
… techniques such as x-ray diffraction and piezoresponse force microscopy. We show, for the first time, the presence of monoclinic distortions and intermediate phases (akin to conventional MPB systems) in the mixed-phase films that are crucial for enhanced electromechanical responses. We …
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Interactions of single-crystal lithium niobate surfaces with ultra-violet laser radiation
… by chemical etching in hydrofluoric acid and by piezoresponse force microscopy and was seen to be most effective on the -z face of the crystal. An explanation was proposed whereby photo-excited charges travel within a pyro-electric field, creating a space-charge field which locally inverts the …
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Thermally modulated solidly mounted resonators for applications in biosensing
… layer in these nanoscale resonators. The piezoresponse force microscopy (PFM) revealed these PE-ALD deposited ZnO films have higher piezoelectric coefficients (approximately 3×) compared to the bulk ZnO.
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Strain-phase relations in lead-free ferroelectric KxNa1-xNbO3 epitaxial films for domain engineering
… have been investigated in detail mainly with the piezoresponse force microscope (PFM). Together with elaborated x-ray diffraction measurements a detailed analysis of the ferroelectric domain structure inherently coupled to the crystal symmetry was possible. First, K0.75Na0.25NbO3 on TbScO3 with …
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Investigating the Thermal Stability and Cation Ordering in Layered Cathode LixMO2 (x ≤ 1; M = Co, Mn, Ni) Materials for Li-ion Rechargeable Batteries and Studying the Ferroelectric Properties of LiNbO3 Nanoparticles
… for these nanoparticles were also confirmed by piezoresponse force microscopy (PFM) and Raman spectroscopy. From PFM measurements, it was observed that both sets of particles exhibited polarization switching at room temperature with static <em>d</em>33 coefficient values of 17 pm/V for cube-like …
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Deposition and characterisation of bismuth layer-structured ferroelectric films
… grains (crystallographic orientations). Piezoresponse force microscopy (PFM) was adopted to characterise BSmT films. Domain structures were clearly observed in a PLD-grown BSmT film, which were closely related to the grain structures. Domain manipulation was carried out in a CSD-derived …
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A Schottky-to-Ohmic Transition in Epitaxial Ferroelectric Hafnia Devices
… Ferroelectricity in the film was confirmed by piezoresponse force microscopy. In device configuration, using an Au top electrode with an ultra-thin Ti adhesion layer, a resistance switching mode with large on-off ratio was observed. The pristine device was stabilised in an intermediate …
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