Structure–property relationships in (1 − x)BaTiO3–xBiGdO3 ceramics

(1 − x)BaTiO3–xBiGdO3 ceramics were prepared by the solid state reaction method. X-ray diffraction and Raman spectroscopy indicate a maximum co-solubility of Bi/Gd in BaTiO3 at x = 0.10 with a change of symmetry from tetragonal to pseudo-cubic at x = 0.08. Backscattered electron images, however, reveal the presence of a secondary phase in x ≥ 0.06. The dielectric behaviour evolves continuously with x from a classical ferroelectric to a typical relaxor and this transition is accompanied by a shift in the permittivity maxima towards lower temperatures. The presence of two dielectric anomalies for x ≥ 0.06 is associated with residual core–shell structures, as revealed by transmission electron microscopy. The dielectric anomaly associated with the core regions remains at ∼120 °C, whereas the other anomaly decreases continuously towards lower temperature with x. This study shows that chemical equilibrium is much more difficult to achieve than in other (1 − x)BaTiO3–xBi[Me]O3 systems, where Me is Yb or Sc

Highly Conductive RuO2_2 Thin Films from Novel Facile Aqueous Chemical Solution Deposition

Ruthenium dioxide (RuO$_2$) thin films were synthesized by Chemical Solution Deposition (CSD) on silicon substrates using only water and acetic acid as solvents. The microstructure, phase-purity, electrical and optical properties as well as the thermal stability of the thin films have been characterized. The microstructure of the thin films strongly depends on the annealing temperature: A smooth thin film was achieved at an annealing temperature of 600$^\circ$C. Higher annealing temperatures (800$^\circ$C) led to radial grain growth and an inhomogeneous thin film. A very low resistivity of 0.89 {\Omega}m was measured for a 220 nm-thick thin film prepared at 600$^\circ$. The resistivity of the thin films increases with temperature, which indicates metallic behavior. Phase-purity of the thin films was confirmed with X-ray Diffraction (XRD) measurements, X-ray Photoelectron Spectroscopy (XPS) and Raman spectroscopy. Transmission and reflectivity measurements indicate that RuO$_2$ efficiently blocks the UV-VIS and IR wavelengths. The optical constants determined via spectroscopic ellipsometry show high absorption in the near-IR region as well as a lower one in the UV-VIS region. The thermal stability was investigated by post-annealing, confirming that the thin films are stable up to 750$^\circ$C in synthetic air.Comment: Journal of Sol-Gel Science and Technology (2023

Bausteine für Ortschronisten und Heimatforscher - Band 2

Erschienen als Kohrener Schriften ; 3. - Wir haben unter dem Titel „Bausteine für Ortschronisten und Heimatforscher, Band II“ eine Reihe von Aufsätzen zusammengefasst, die in den vergangenen drei Jahren im Rahmen eines Projektes zur Unterstützung Ehrenamtlicher in der Heimatforschung entstanden sind. Sie gehen zurück auf Vorträge, die bei den Fachtagen in Kohren-Sahlis sowie bei Archivtagungen in Chemnitz und Dresden gehalten worden sind. Schon der erste gleichnamige Band, der 2017 erschien, erfreute sich außerordentlicher Beliebtheit, was uns ermutigte, die Reihe fortzusetzen. Dabei ist der Name programmatisch zu verstehen, denn wir können Heimatforschenden kein umfängliches Handbuch liefern, wohl aber einzelne Bausteine, aus denen man sich, die für die Arbeit geeigneten auswählen kann. Die Texte nehmen ganz praktische Fragestellungen der Heimatforschenden auf und verstehen sich als Werkzeuge und geben Anregungen für ihre weitere Arbeit. Dabei ist der Bogen weit gespannt und reicht von der Beschäftigung mit dem Pass- und Meldewesen im 19. und 20. Jahrhundert, über die Anleitung zurErstellung einer Häuserchronik bis zur Frage nach der historischen Aussagekraftvon Dachbodenfunden. All das spiegelt letztlich die Bandbreite derThemen, mit denen sich Heimatforschende auseinandersetzen.Ermöglicht wurde der vorliegende zweite Band der Bausteine letztlichdurch das Projekt zur „Unterstützung des freiwilligen Engagements in derHeimatforschung im ländlichen Raum Sachsens“, das seit 2017 beim SächsischenLandeskuratorium Ländlicher Raum e.V. angesiedelt ist.:Inhaltsverzeichnis Vorwort Michael Wetzel: Das frühneuzeitliche Dorf als Gegenstand der Heimatforschung Lutz Vogel: „Papiere“ als moderne Herrschaftsinstrumente: Ein Streifzug durch die Geschichte des Passwesens Michael Wetzel: Wie erstelle ich eine Häuserchronik meines Ortes für die Frühe Neuzeit? Eine Handreichung für Heimatforscher Jens Kunze: Gerichtsbücher als wertvolle Quellen für die Heimatforschung Cornelia Neustadt und Sabine Zinsmeyer: Inschriften als landesgeschichtliche Quellen. Epigrafik für Heimatforschende Christian Meyer: Der Wandel des ländlichen Hausbaues in Sachsen – Eine Literaturempfehlung Meike Leyde: Vom Dachbodenfund zum Museumsobjekt. Zum Umgang mit historischen Alltagsgegenständen Jan Graupner: Die Wahrung von Persönlichkeitsrechten in Ortschroniken Autorinnen und Autoren in diesem Band Impressu

Bismuth Sodium Titanate Based Materials for Piezoelectric Actuators

The ban of lead in many electronic products and the expectation that, sooner or later, this ban will include the currently exempt piezoelectric ceramics based on Lead-Zirconate-Titanate has motivated many research groups to look for lead-free substitutes. After a short overview on different classes of lead-free piezoelectric ceramics with large strain, this review will focus on Bismuth-Sodium-Titanate and its solid solutions. These compounds exhibit extraordinarily high strain, due to a field induced phase transition, which makes them attractive for actuator applications. The structural features of these materials and the origin of the field-induced strain will be revised. Technologies for texturing, which increases the useable strain, will be introduced. Finally, the features that are relevant for the application of these materials in a multilayer design will be summarized

Alternative Splicing of Fibroblast Growth Factor Receptor IgIII Loops in Cancer

Alternative splicing of the IgIII loop of fibroblast growth factor receptors (FGFRs) 1–3 produces b- and c-variants of the receptors with distinctly different biological impact based on their distinct ligand-binding spectrum. Tissue-specific expression of these splice variants regulates interactions in embryonic development, tissue maintenance and repair, and cancer. Alterations in FGFR2 splicing are involved in epithelial mesenchymal transition that produces invasive, metastatic features during tumor progression. Recent research has elucidated regulatory factors that determine the splice choice both on the level of exogenous signaling events and on the RNA-protein interaction level. Moreover, methodology has been developed that will enable the in depth analysis of splicing events during tumorigenesis and provide further insight on the role of FGFR 1–3 IIIb and IIIc in the pathophysiology of various malignancies. This paper aims to summarize expression patterns in various tumor types and outlines possibilities for further analysis and application

Multiferroic and magnetoelectric properties of Pb0.99[Zr0.45Ti0.47(Ni1/3Sb2/3)0.08]O3–CoFe2O4 multilayer composites fabricated by tape casting

A 2-2 type multiferroic composite device encompassing three CoFe2O4 (CFO) layers confined between four Pb0.99[Zr0.45Ti0.47(Ni1/3Sb2/3)0.08]O3 (PZT) layers was fabricated by tape casting. X-ray diffraction data showed good chemical compatibility between the two phases, whereas Scanning Electron Microscopy imaging also revealed an intimate contact between CFO and PZT layers. Under an applied electric field of 65 kV/cm, this multilayer device shows a saturated polarisation of 7.5 C/cm2 and a strain of 0.12%, whereas under a magnetic field of 10 kOe it exhibits a typical ferromagnetic response and a magnetic moment of 33 emu/g. These devices can be electrically poled, after which they exhibit magnetoelectric coupling

Olfactory fMRI in Patients with Parkinson's Disease

Hyposmia is one of the early signs in idiopathic Parkinson's disease (PD). Olfactory stimuli were applied during fMRI scanning to show disease-related modulation of central nervous system structures and to advance our understanding of olfactory dysfunction in PD patients. All participants received either unpleasant stimuli that smelled like rotten eggs or pleasant ones that smelled like roses. Using a block design at a 1.5 T scanner we investigated a total of 8 PD patients (mean age 60 ± 10.9 years) and 13 age matched controls (mean age 58 ± 9.6 years). PD duration ranged from 1 to 9 years (mean 6.63 years); patients had an average “Unified Parkinson's Disease Rating Scale III” score of 23.25 (range, 6–46). Olfactory function was established using the “Sniffin’ Sticks” test battery. Patients tended to rate the stimuli presented during fMRI scans as less intense, but also as more pleasant than controls. fMRI results revealed differences between PD patients and controls which depended on the type of stimulation. While both pleasant and unpleasant stimulation was associated with lower activation in the amygdalo–hippocampal complex in patients compared to controls, increased activity in response to pleasant stimuli was observed in the striatum and the left inferior frontal gyrus. In contrast, unpleasant stimulation led to hypoactivation of the ventral striatum in patients (but not in controls) and did not enhance left inferior frontal activity. These results may partly reflect differences between PD patients and healthy controls in the processing of primary dimensions of odors, intensity, and valence

Yttrium Iron Garnet/Barium Titanate Multiferroic Composites

Dense multiferroic 0-3 type composites encompassing BaTiO3 and Y3Fe5O12 were fabricated by the solid state reaction method. X-ray diffraction data combined with Scanning Electron Microscopy imaging show virtual immiscibility between the two phases, with the Y3Fe5O12 ferrimagnetic phase well dispersed in the tetragonal BaTiO3 ferroelectric matrix. Raman spectroscopy analyses corroborate the polar nature of the BaTiO3 matrix in composites with a Y3Fe5O12 content as great as 40 wt%. Ferrimagnetism is detected in all composites and no additional magnetic phases are distinguished. Although these dense ceramics can be electrically poled, they exhibit a very weak magnetoelectric response, which slightly increases with Y3Fe5O12 content

Synergistic Homovalent and Heterovalent Substitution Effects on Piezoelectric and Relaxor Behavior in Lead-Free BaTiO3 Ceramics

This study investigates lead-free BaTiO3 (BT) perovskite ceramics, unraveling the synergistic effects arising from simultaneous homovalent (Zr) and heterovalent (Nb) substitution. Focusing on piezoelectric, ferroelectric, and relaxor behaviors, this research employs a comprehensive suite of analyses, including temperature-dependent dielectric measurements, polarization-electric field hysteresis loops, and bipolar strain measurements. Significantly, our study unveils that the simultaneous substitution of Zr and Nb in the BT lattice induces room-temperature relaxor behavior at relatively low concentrations (5% Zr and 3% Nb), yielding higher permittivity and larger maximum polarization compared to single element (Zr or Nb) substituted BT relaxors. Bipolar strain measurements showcase substantial large-signal d 33 ⁎ values (~250pm/V) across a broad temperature range (–50 °C to 30 °C) for BT ceramics with simultaneous 5% Zr and 2% Nb substitution. This research advances understanding of homovalent and heterovalent substitution in BT ceramics and opens avenues for tailoring properties to suit specific applications

Influence of orbital contributions to the valence band alignment of Bi2O3, Fe2O3, BiFeO3, and Bi0.5Na0.5TiO3

The formation of an interface between Bi2O3, Fe2O3, BiFeO3, Bi0.5Na0.5TiO3, and the high work function metallic RuO2 is studied using photoelectron spectroscopy with in situ RuO2 deposition. Schottky barrier heights are derived and the valence band maximum energies of the studied materials are aligned with respect to each other as well as to other functional oxides like SrTiO3 and PbTiO3. The energy band alignment follows systematic trends compared to a large number of oxides, and can be understood in terms of the contribution of Fe 3d and Bi 6s/6p (lone pair) orbitals to electronic states near the valence band maximum. The results indicate that the valence band maxima are largely determined by the local environment of the cations, which allows to estimate valence band maximum energies of oxides with multiple cations from those of their parent binary compounds. The high valence band maximum of BiFeO3 is consistent with reported p-type conduction of acceptor doped material, while the high conduction band minimum makes n-type conduction unlikely