Fabrication of Large-Area High-Resolution Templates by Focused Ion Beam Combined with Colloidal Nanoparticle Dimer Deposition for SERS Substrates.

This article presents an examination of well-controlled patterns created using a Ga-based focused ion beam (FIB) on glass, while silicon substrates were used to evaluate the FIB performance by its achievable feature size versus time constraints. The pattern creation on glass was developed with the aim of studying potential surface-enhanced Raman spectroscopy (SERS) applications. Furthermore, the FIB was used to create dimer systems of periodically and randomly positioned dumbbell-shaped pits on the glass (each dimer occupies an area of 203 × 87 nm).

Luminescence, XPS and Raman of crystalline quartz affected to high pressure by detonation.

The Raman spectra, x-ray photoelectron spectroscopy (XPS), and x-ray excited luminescence spectra of crystalline quartz samples subjected to different pressure levels through detonation were compared with the spectra of the original samples. In the samples under study, the luminescence of a self-trapped exciton (STE) was analyzed, which, when excited by x-rays, has a high energy yield (∼20%) in crystalline-quartz not treated by detonation. The deviations of the luminescence spectrum are small in the pressure range from 9 to 27 GPa relative to untreated samples, which means the presence of crystalline quartz grains.

High-order harmonics generation in Cd and Pd laser-induced plasmas.

We demonstrate the generation of high-order harmonics of laser pulses in palladium and cadmium plasmas. We adjusted the wavelength of driving pulses to investigate the resonance enhancement in different ranges of extreme ultraviolet region. The summation of incommensurate waves during the two-color pump of Pd and Cd plasmas allowed the generation of a broader range of harmonics.

Amorphous Calcium Phosphate and Amorphous Calcium Phosphate Carboxylate: Synthesis and Characterization.

Amorphous calcium phosphate (ACP) is the first solid phase precipitated from a supersaturated calcium phosphate solution. Naturally, ACP is formed during the initial stages of biomineralization and stabilized by an organic compound. Carboxylic groups containing organic compounds are known to regulate the nucleation and crystallization of hydroxyapatite.

Tribovoltaic Performance of TiO Thin Films: Crystallinity, Contact Metal, and Thermoelectric Effects.

Tribovoltaic devices are attracting increasing attention as motion-based energy harvesters due to the high local current densities that can be generated. However, while these tribovoltaic devices are being developed, debate remains surrounding their fundamental mechanism. Here, we fabricate thin films from one of the world's most common oxides, TiO, and compare the tribovoltaic performance under contact with metals of varying work functions, contact areas, and applied pressure.

Synthesis and Investigation of Novel Optical Active SiO Glasses with Entrapped YAG:Ce Synthesized via Sol-Gel Method.

We present a crack-free optically active SiO glass-composite material containing YAG:Ce synthesized via a modified sol-gel technique. A glass-composite material consisting of yttrium aluminum garnet doped with Ce (YAG:Ce) was entrapped into a SiO xerogel. This composite material was prepared using a sol-gel technique with modified gelation and a drying process to obtain crack-free optically active SiO glass.

Effect of Post-Printing Cooling Conditions on the Properties of ULTEM Printed Parts.

This paper aimed to estimate the effect of post-printing cooling conditions on the tensile and thermophysical properties of ULTEM 9085 printed parts processed by fused deposition modeling (FDM). Three different cooling conditions were applied after printing Ultem samples: from 180 °C to room temperature (RT) for 4 h in the printer (P), rapid removal from the printer and cooling from 200 °C to RT for 4 h in the oven (O), and cooling at RT (R). Tensile tests and dynamic mechanical thermal analysis (DMTA) were carried out on samples printed in three orthogonal planes to investigate the effect of the post-printing cooling conditions on their mechanical and thermophysical properties.

Hydrothermal Synthesis and Properties of Yb/Tm Doped SrLaF Upconversion Nanoparticles.

We report the procedure for hydrothermal synthesis of ultrasmall Yb/Tm co-doped SrLaF (SLF) upconversion phosphors. These phosphors were synthesized by varying the concentrations of Yb (x = 10, 15, 20, and 25 mol%) and Tm (y = 0.75, 1, 2, and 3 mol%) with the aim to analyze their emissions in the near IR spectral range.

Enhanced optical properties of yttrium aluminum garnet with the yttrium vanadate impurity phase.

Yttrium aluminum garnet doped with europium with an additional impurity phase of yttrium vanadate doped europium has been prepared in different ways: synthesized by a sol-gel route and mechanically mixed in a mortar. The obtained samples were characterized by X-ray diffraction analysis, and scanning electron microscopy. Photoluminescence spectra were recorded to understand the role of the impurity phase in the garnet's optical properties.

Effect of Core-Shell Rubber Nanoparticles on the Mechanical Properties of Epoxy and Epoxy-Based CFRP.

The aim of the research was to estimate the effect of core-shell rubber (CSR) nanoparticles on the tensile properties, fracture toughness, and glass transition temperature of the epoxy and epoxy-based carbon fiber reinforced polymer (CFRP). Three additives containing CSR nanoparticles were used for the research resulting in a filler fraction of 2-6 wt.% in the epoxy resin.

Investigation of Nonlinear Optical Processes in Mercury Sulfide Quantum Dots.

The authors report the third-harmonic generation, nonlinear refraction, and nonlinear absorption in HgS quantum dot (QD) suspensions and films using the nanosecond and femtosecond pulses. High conversion efficiency (7 × 10) towards the third harmonic (TH) of the 900-1700 nm, 150 fs laser in the thin (70 nm) films containing HgS QDs deposited on the glass substrates is obtained. The authors analyze spectral dependencies of the TH, nonlinear refractive indices, and nonlinear absorption coefficients of QDs in the 500-1700 nm range and discuss the relation between the TH process and the low-order nonlinear optical properties of these quantum dots.

Unraveling the Structure and Properties of Layered and Mixed ReO-WO Thin Films Deposited by Reactive DC Magnetron Sputtering.

Tungsten trioxide (WO) is a well-known electrochromic material with a wide band gap, while rhenium trioxide (ReO) is a "covalent metal" with an electrical conductivity comparable to that of pure metals. Since both WO and ReO oxides have perovskite-type structures, the formation of their solid solutions (ReO-WO or Re W O) can be expected, which may be of significant academic and industrial interest. In this study, layered WO/ReO, ReO/WO, and mixed ReO-WO thin films were produced by reactive DC magnetron sputtering and subsequent annealing in air at 450 °C.

Oxidation State and Local Structure of Chromium Ions in LaOCl.

LaOCl doped with 0-10 mol% Cr was synthesized by thermal decomposition of chlorides. X-ray diffraction (XRD) analysis revealed that incorporation of chromium results in a decrease of the lattice parameter and a simultaneous increase of the lattice parameter . The local structure of chromium ions was studied with X-ray photoelectron (XPS), X-ray absorption (XANES), multifrequency electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) spectroscopy techniques.

Time-resolved luminescence and excitation spectroscopy of Co-doped GdGaAlO scintillating crystals.

Cerium doped GdGaAlO (GGAG) single crystals as well as GGAG:Ce single crystals co-doped by divalent (Mg, Ca) and tetravalent (Zr, Ti) ions have been studied by means of time-resolved luminescence as well as the excitation luminescence spectroscopy in vacuum ultraviolet (VUV) and soft X-ray (XUV) spectral range. Tunable laser excitation was applied for time-resolved experiments in order to obtain luminescence decay curves under excitations in Ce, Gd and excitonic absorption bands. The influence of the co-dopant ions on the Ce luminescence decay kinetics is elucidated.