A5028690491- Ferroelectric and Piezoelectric Materials
- Multiferroics and related materials
- Acoustic Wave Resonator Technologies
- Ferroelectric and Negative Capacitance Devices
- Magnetic and transport properties of perovskites and related materials
- Advanced Memory and Neural Computing
- Electronic and Structural Properties of Oxides
- Microwave Dielectric Ceramics Synthesis
- Semiconductor materials and devices
- Advanced Condensed Matter Physics
- Solid-state spectroscopy and crystallography
- Dielectric properties of ceramics
- MXene and MAX Phase Materials
- Transition Metal Oxide Nanomaterials
- Magnetic properties of thin films
- Advanced Sensor and Energy Harvesting Materials
- Force Microscopy Techniques and Applications
- Conducting polymers and applications
- Magnetic Properties and Synthesis of Ferrites
- Nonlinear Optical Materials Research
- Photorefractive and Nonlinear Optics
- Material Properties and Applications
- Theoretical and Computational Physics
- Glass properties and applications
- Inorganic Chemistry and Materials
University of Groningen
2016-2025
Czech Academy of Sciences, Institute of Physics
2020
Institut Català de Nanociència i Nanotecnologia
2020
Universitat Autònoma de Barcelona
2020
University of Illinois Urbana-Champaign
2020
Centre National de la Recherche Scientifique
2020
Institució Catalana de Recerca i Estudis Avançats
2020
University of Twente
2020
Leibniz Institute for High Performance Microelectronics
2020
Institute for Microelectronics and Microsystems
2020
High resolution x-ray powder diffraction measurements on poled PbZr1-xTixO3 (PZT) ceramic samples close to the rhombohedral-tetragonal phase boundary (the so-called morphotropic boundary) have shown that for both rhombohedral and tetragonal compositions piezoelectric elongation of unit cell does not occur along polar directions but those associated with monoclinic distortion. This work provides first direct evidence origin very high piezoelectricity in PZT.
A previously unreported ferroelectric phase has been discovered in a highly homogeneous sample of PbZr0.52Ti0.48O3 by high-resolution synchrotron x-ray powder diffraction measurements. At ambient temperature the tetragonal symmetry (at=4.037 Å, ct=4.138 Å), and transforms below ∼250 K into which, unexpectedly, monoclinic (am=5.717 bm=5.703 cm=4.143 β=90.53°, at 20 K). The intensity data strongly indicate that polar axis lies ac plane close to pseudocubic [111] direction, which would be an...
The perovskitelike ferroelectric system ${\mathrm{PbZr}}_{1\ensuremath{-}x}{\mathrm{Ti}}_{x}{\mathrm{O}}_{3}$ (PZT) has a nearly vertical morphotropic phase boundary (MPB) around $x=0.45--0.50.$ Recent synchrotron x-ray powder diffraction measurements by Noheda et al. [Appl. Phys. Lett. 74, 2059 (1999)] have revealed monoclinic between the previously established tetragonal and rhombohedral regions. In present work we describe Rietveld analysis of detailed structure PZT phases on sample with...
Synchrotron x-ray powder diffraction measurements have been performed on unpoled ceramic samples of $(1\ensuremath{-}x)\mathrm{Pb}({\mathrm{Mg}}_{1/3}{\mathrm{Nb}}_{2/3}){\mathrm{O}}_{3}\ensuremath{-}x{\mathrm{PbTiO}}_{3}$ (PMN-xPT) with $30%<~x<~39%$ as a function temperature around the morphotropic phase boundary, which is line separating rhombohedral and tetragonal phases in diagram. The experiments revealed very interesting features previously unknown this or related systems. sharp...
The origin of ultrahigh piezoelectricity in the relaxor ferroelectric PbZn1/3Nb2/3O3-PbTiO3 was studied with an electric field applied along [001] direction. zero-field rhombohedral R phase starts to follow direct polarization path tetragonal symmetry via intermediate monoclinic M phase, but then jumps irreversibly alternate involving a different type distortion. Details structure and domain configuration this novel are described. This result suggests that there is nearby R-M boundary as...
Recent structural studies of ferroelectric ${\mathrm{PbZr}}_{1\ensuremath{-}x}{\mathrm{Ti}}_{x}{\mathrm{O}}_{3}$ (PZT) with $x=0.48,$ have revealed a monoclinic phase in the vicinity morphotropic boundary (MPB), previously regarded as separating rhombohedral and tetragonal regions PZT diagram. In present paper, stability region all three phases has been established from high-resolution synchrotron x-ray powder-diffraction measurements on series highly homogeneous samples...
Local conduction at domains and domain walls is investigated in BiFeO(3) thin films containing mostly 71° walls. Measurements room temperature reveal through Conduction could also be observed high enough temperatures. It found that, despite the lower conductivity of domains, both are governed by same mechanisms: low voltage regime, electrons trapped defect states activated but current limited ferroelectric surface charges; large Schottky emission takes place role oxygen vacancies that...
Unconventional ferroelectricity exhibited by hafnia-based thin films-robust at nanoscale sizes-presents tremendous opportunities in nanoelectronics. However, the exact nature of polarization switching remains controversial. We investigated a La0.67Sr0.33MnO3/Hf0.5Zr0.5O2 capacitor interfaced with various top electrodes while performing situ electrical biasing using atomic-resolution microscopy direct oxygen imaging as well synchrotron nanobeam diffraction. When electrode is reactive, we...
Ferroelectric hafnium and zirconium oxides have undergone rapid scientific development over the last decade, pushing them to forefront of ultralow-power electronic systems. Maximizing potential application in memory devices or supercapacitors these materials requires a combined effort by community address technical limitations, which still hinder their application. Besides favorable intrinsic material properties, HfO2–ZrO2 face challenges regarding endurance, retention, wake-up effect, high...
A ferroelectric monoclinic phase of space group Cm ${(M}_{A}$ type) has been discovered in $0.65{\mathrm{P}\mathrm{b}(\mathrm{M}\mathrm{g}}_{1/3}{\mathrm{Nb}}_{2/3}{)\mathrm{O}}_{3}{\ensuremath{-}0.35\mathrm{}\mathrm{PbTiO}}_{3}$ by means high-resolution synchrotron x-ray diffraction. It appears at room temperature a single crystal previously poled under an electric field 43 kV/cm applied along the pseudocubic [001] direction, region diagram around morphotropic boundary between rhombohedral...
Recently, a new orthorhombic phase has been discovered in the ferroelectric system Pb(Zn1/3Nb2/3)O3-xPbTiO3 (PZN-xPT) for x= 9%, and 8% after application of an electric field. In present work, synchrotron x-ray measurements have extended to higher concentrations, 10% <= x <=15%. The was observed 10%, but, surprisingly, x>= 11% only tetragonal found down 20 K. thus exists narrow concentration range with near vertical boundaries on both sides. This symmetry (MC-type) is contrast monoclinic...
Strong piezoelectricity in the perovskite-type PbZr(1-x)TixO3 (PZT) and Pb(Zn1/3Nb2/3)O3-PbTiO3 (PZN-PT) systems is generally associated with existence of a morphotropic phase boundary (MPB) separating regions rhombohedral tetragonal symmetry. An x-ray study PZN-9%PT has revealed presence new orthorhombic at MPB, near-vertical between phases, similar to that found for PZT monoclinic phases. We discuss results light recent theoretical paper by Vanderbilt Cohen, which attributes these...
X-ray analysis of ferroelectric thin layers Ba1/2Sr1/2TiO3 with different thickness reveals the presence internal strain gradients across film and allows us to propose a functional form for profile. We use this calculate direct influence gradient, through flexoelectric coupling, on degradation properties films decreasing thickness, in excellent agreement observed behaviour. This work highlights link between relaxation epitaxial films, shows pressing need avoid order obtain ferroelectrics...
Ceramic solid solutions of PbZr1− x T O3 (PZT) with compositions x≃ 0.50 are well-known for their extraordinarily large piezoelectric responses. The latter highly anisotropic, and it was recently shown that, the rhombohedral (x ≲ 0.5), coefficients were largest away from polar direction, contrary to common belief. Shortly afterwards a low-symmetry monoclinic phase observed by synchrotron X-ray diffraction at around = 0.50. Similar behavior features also present in number related lead-based...
High-energy x-ray-diffraction experiments performed on rhombohedral $\mathrm{Pb}({\mathrm{Zn}}_{1/3}{\mathrm{Nb}}_{2/3}{)}_{1\ensuremath{-}x}{\mathrm{Ti}}_{x}{\mathrm{O}}_{3}$ $(\mathrm{PZN}\ensuremath{-}x%\mathrm{PT})$ crystals with $x=4.5%$ and 8% show that an electric field applied along the [001] direction induces tetragonal phase, as proposed by Park Shrout. Our reveal in PZN-4.5%PT such a phase change occurs via third monoclinic symmetry ${M}_{A},$ which is observed at intermediate...
The microstructure and phase transition in relaxor ferroelectric $\mathrm{Pb}({\mathrm{Mg}}_{1/3}{\mathrm{Nb}}_{2/3}){\mathrm{O}}_{3}$ (PMN) its solid solution with ${\mathrm{PbTiO}}_{3}$ (PT), $\mathrm{PMN}\ensuremath{-}x\mathrm{PT},$ remain to be some of the most puzzling issues solid-state science. In present work we have investigated evolution symmetry $\mathrm{PMN}\ensuremath{-}x\mathrm{PT}$ ceramics as a function temperature $(20<T<500\mathrm{K})$ composition $(0<~x<~0.15)$ by means...
Thin films of PbTiO3, a classical ferroelectric, have been grown under tensile strain on single-crystal substrates DyScO3. The films, only 5 nm thickness, grow fully coherent with the substrate, as evidenced by synchrotron x-ray diffraction. A mapping reciprocal space reveals intensity modulations (satellites) due to regularly spaced polar domains in which polarization appears rotated away from substrate normal, characterizing low-symmetry phase not observed bulk material. This could...