Microstructural evolution of dense and porous pyroelectric Pb1−xCaxTiO3 thin films

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We experimentally demonstrate a differential microscopy methodology that facilitates simultaneous amplitude, phase, and differential polarization imaging. The proposed optical spatial differentiator is obtained in a remarkably simple setup by placing a glass cover slip, acting as a signum phase mask in the Fourier plane of a standard 4f imaging arrangement. Unlike conventional approaches, the scheme operates without polarized illumination, thereby enabling polarization to serve as an additional contrast wit

We investigate the influence of AlN buffer thickness on the structural, electrical, and thermal properties of AlGaN/GaN high-electron mobility transistors (HEMTs) grown on semi-insulating SiC substrates by metal-organic chemical vapor deposition. X-ray diffraction and atomic force microscopy reveal that while thin AlN layers (120 nm) exhibit compressive strain and smooth step-flow surfaces, thicker single-layer buffers (550 nm) develop tensile strain and increased surface roughness. Multi-layer buffer struc

Since their discovery, scanning probe microscopy (SPM) and scanning electron microscopy (SEM) techniques have been extensively employed across diverse research fields for nanoscale characterization and analysis. While their ex-situ combination has been widely used, the in-situ integration of the two techniques has gained significant traction in recent years. This review highlights the journey of bringing the complementary capabilities of these two instruments into a single platform, with the focus on extrac

Natural biocomposites such as wood and plant cell walls exhibit prominent mechanical properties largely attributed to the nanoscale organization of fibrous components, such as cellulose, which often adopt chiral arrangements. However, resolving the three-dimensional (3D) arrangement of these structures at the nanoscale remains a significant challenge, particularly in beam-sensitive materials. This study introduces a method for 3D reconstruction of orientation based on scanning electron diffraction (SED), en

Preferred particle orientation remains a frequently encountered issue in cryo-electron microscopy that arises when proteins adsorb to the air-water interface in only a limited number of orientations. This can significantly increase the data acquisition time required to reach a desired resolution or even make it impossible to obtain a reconstruction altogether. Here, we show that preferred orientation can be overcome by continuously exciting the sample with ultrasonic waves during vitrification. Our experime

Pseudo-heterodyne scattering-type scanning near-field optical microscopy (sSNOM) is applied in the mid-infrared region to detect the chemical composition of biomolecules on the nanoscale. However, the application of sSNOM in molecular biology has been limited to static images in air. Recently, bottom illumination sSNOM (BI-sSNOM) was developed for operation in water. Yet, the scan rate of sSNOM remains a bottleneck to record protein structural changes in aqueous solution on the seconds time scale. We design

Gyrokinetic simulations are extensively used as a tool to describe various phenomena in magnetically confined plasmas. Among others, turbulent transport induced by drift-wave type instabilities such as Ion Temperature Gradient (ITG), Trapped Electron Mode (TEM) and Electron Temperature Gradient (ETG) plays a central role in fusion research. While the ITG mode in first approximations can be modeled using a reduced adiabatic electron model, the TEM and ETG modes require a kinetic description. The global delta

Environmental transmission electron microscopy was used to characterize in situ the reduction and oxidation of nickel from a Ni/YSZ solid oxide fuel cell anode support between 300-500°C. The reduction is done under low hydrogen pressure. The reduction initiates at the NiO/YSZ interface, then moves to the center of the NiO grain. At higher temperature the reduction occurs also at the free NiO surface and the NiO/NiO grain boundaries. The growth of Ni is epitaxial on its oxide. Due to high volume decrease, na

Systems with a ferroelectric to paraelectric transition in the vicinity of room temperature are useful for devices. Adjusting the ferroelectric transition temperature (T-c) is traditionally accomplished by chemical substitution - as in BaxSr1-xTiO3, the material widely investigated for microwave devices in which the dielectric constant (epsilon(r)) at GHz frequencies is tuned by applying a quasi-static electric field(1,2). Heterogeneity associated with chemical substitution in such films, however, can broad

Three wet chemistry routes were used to synthesize Ba0.99Zr0.8Y0.2O3-delta (BZY20) and to avoid the drawbacks of the conventional mixed oxide route used for its preparation. Pure samples were prepared using the Matrix Trapping and Decomposition (MTD) and Polyacrylamide Gel (PG) processes. The compound as a powder is thermodynamically stable up to 1250 degreesC while the purity of the bulk of a pellet can be maintained up to 1500 degreesC. An expected increase of the lattice parameter (from 0.4193 (BaZrO3) t

PZT (PbZrx Ti1-xO3) thin films have been locally grown by means of sol-gel deposition and local annealing on microhotplates. The microhotplates were based on a stress compensated Si3N4 /SiO2 membranes as structural elements and contained tantalum silicide filaments (Ta5Si3) for resistive heating. Above the filaments, a passivation layer of SiO2, an adhesion layer of Ti/TiO2 and a bottom electrode of Pt were deposited. Due to the low heat conductivity of the membrane, crystallization of the PZT film occurs e

Electromechanical properties of a number of ferroelectric films including PbZrxTi1-xO3(PZT), 0.9PbMg(1/3)Nb(2/3)O(3)-0.1PbTiO(3)(PMN-PT), and SrBi2Ta2O9(SBT) are investigated using laser interferometry combined with conventional dielectric measurements. Effective electrostriction coefficients of the films, Q(eff), are determined using a linearized electrostriction equation that couples longitudinal piezoelectric coefficient, d(33), with the polarization and dielectric constant. It is shown that, in PZT film

Nickel-aluminium intermetallics constitute interesting systems for the study of irradiation-induced phase transformations (order → disorder, amorphization) and production of defects. Irradiation of ordered intermetallics may induce disorder or amorphization depending on the projectile characteristics, irradiation conditions and chemical and physical properties of the target. The behavior of the various intermetallic compounds of the nickel-aluminium system with respect to electron and ion irradiation has be

OBJECTIVE: In tissue engineering, three-dimensional biodegradable scaffolds are generally used as a basic structure for cell anchorage, cell proliferation and cell differentiation. The currently used biodegradable scaffolds in cardiovascular tissue engineering are potentially immunogenic, they show toxic degradation and inflammatory reactions. The aim of this study is to establish a new three-dimensional cell culture system within cells achieve uniform distribution and quick tissue development and with no t

In YBa2Cu3O6+x the tetragonal to orthorhombic transition occurs around x equals 0.3, followed by a continuum variation of lattice parameters. Hence both, the structural and superconducting properties, depend upon the oxygen content in CuO chains. Conversely, the epitaxial stress, exerted by the substrate on YBCO films, modified the lattice parameters, influencing the oxygen stability in the chains. The understanding of this mechanism is essential when growing epitaxial films for in-situ photoemission studie

Crystalline diamond coatings and, increasingly, diamond-like amorphous carbon (DLC) films are used for tribological and protective layers for their hardness and chemical inertness. They are also under investigation for their electron emitting properties, with possible applications in field emission displays. In this study, hydrogen-free DLC films were deposited by laser ablation using a KrF excimer laser and fluences between 0.5 and 2 J/cm(2). Information about the disorder and short range order in the film

The minimal photounit of the photosynthetic membranes of the purple non-sulfur bacterium Rhodospirillum rubrum, comprising the reaction center and the light-harvesting complex has been purified and crystd. in two dimensions in the presence of added phospholipids, and subsequently visualized by electron microscopy after neg.-staining. The position of the reaction centers within the light-harvesting ring has been detd. at low resoln. by the application of a new anal. for rotationally disordered identical unit

Platinum silicide films are widely used in silicon devices for ohmic and Schottky contacts. It has been demonstrated in the recent years that Schottky barriers employing ultra-thin platinum silicide films (thickness < 10 nm) are useful for photodetection in the near infrared. We have studied the formation of thin platinum silicide films and their electrical properties as a function of the annealing temperature in presence of an interfacial native silicon oxide layer and with plasma etching damage on the Si

We present results obtained both with scanning electron microscopy (SEM) in the cathodoluminescence (CL) mode and transmission electron microscopy (TEM) on ZnCdSe/ZnSe electron-beam-pumped laser structures. This investigation aims at establishing a relationship between different parameters measurable in electron microscopy and the lasing activity of the structures.

This paper presents some recent research on the microstructural development during alkaline activation of slag pastes. Pastes of different slags activated with a range of activators have been prepared and some preliminary results from the study of the pastes activated with sodium hydroxide and waterglass solutions are presented. X-ray diffraction (XRD), differential thermal analysis (DTA), backscattered electron (BSE) imaging of polished samples in the SEM coupled with X-ray microanalysis, and secondary ele

Microstructural evolution of dense and porous pyroelectric Pb1−xCaxTiO3 thin films

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Fourier optical route toward multimodal differential microscopy

Impact of AlN buffer thickness on electrical and thermal characteristics of AlGaN/GaN/AlN HEMTs

A Comprehensive Analysis of Combined AFM/SEM Systems for In-Situ Nanoscale Characterizations and Multiparametric Correlative Microscopy

Chiral Hierarchies at the Nanoscale Revealed by Three-Dimensional Scanning Electron Diffraction

Overcoming Preferred Orientation in Cryo-EM With Ultrasonic Excitation During Vitrification

Separate-scan atomic force microscope for fast infrared scattering-type scanning near-field optical microscope

An improved hybrid electron model for global gyrokinetic simulations using the ORB5 PIC code

In situ reduction and oxidation of nickel from solid oxide fuel cells in a Titan ETEM

Room-temperature ferroelectricity in strained SrTiO3

Preparation, sintering, and water incorporation of proton conducting Ba0.99Zr0.8Y0.2O3-delta: comparison between three different synthesis techniques

Local growth of sol-gel films by means of microhotplates

Characterization of the effective electrostriction coefficients in ferroelectric thin films

The order-disorder transformation and microstructure evolution in nickel-aluminium intermetallics after heavy-ion irradiation

Fibrin gel as a three dimensional matrix in cardiovascular tissue engineering

Structural properties of strained YBa2Cu3O6+x superconducting films grown by pulsed laser deposition

Characterization of diamond-like carbon by Raman spectroscopy, XPS and optical constants

The reaction center of the photounit of Rhodospirillum rubrum is anchored to the light-harvesting complex with four-fold rotational disorder

Formation and properties of nanometer-thick platinum silicide layers

Cathodoluminescence and transmission electron microscopy investigation of ZnCdSe/ZnSe electron-beam-pumped laser structures

Hydration products of alkali activated slag cement