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In this paper, we report on the synthesis of strontium oxide nanoparticles (SONPs) using a novel probe sonication method. Powder X-ray diffraction (PXRD) was used to characterize the physicochemical properties of the prepared materials, which confirmed that the average SrO crystallite size was 43 nm. The Kubelka-Monk function of diffuse reflectance spectroscopy (DRS) was used to confirm the average energy gap of SONPs (4.06 eV). SONPs have been successfully used in conjunction with inventive photocatalysts to remove dyes such as Methylene Blue (MB) and Acid Green (AG). MBand AG dyes were used as standard dyes to investigate the photocatalytic properties of NPs when exposed to UV light and sunlight. These nanometal oxides photodegrade methylene blue (87.70%) and acid green (71.20%) dyes with remarkable efficiency when exposed to UV light. These nanometal oxides demonstrated superior sensitivity when paracetamol was used as an analyte in cyclic voltammetry tests at various scan speeds (10 mV/s to 50 mV/s). As a result, SONPs may be useful in photocatalytic activity and electrochemical sensor applications. [ABSTRACT FROM AUTHOR]

In this study, we successfully synthesized rare-earth-doped crystalline SrWO4 at room temperature by co-precipitation. The results from the X-ray diffraction analysis showed a main diffraction peak related to the (112) plane. Phosphors doped with either Dy3+ or Sm3+ ions showed strong light absorption in the UV region and blue-yellow and red light emission. To synthesize a white light phosphor, Dy3+ and Sm3+ ions were co-doped to produce a SrWO4:[Sm3+]/[Dy3+] phosphor. When the Sm3+ ion concentration was increased and the Dy3+ concentration was maintained, the red light intensity increased while the blue-yellow light intensity decreased. The composites were combined with polydimethylsiloxane (PDMS), and a flexible composite material was fabricated. The composite exhibited various luminescence properties under UV and visible light, which suggested its potential for use as an LED color filter. [ABSTRACT FROM AUTHOR]

Improper disposal of pharmaceutical drugs, including antibiotics, can affect the ecological system and generate serious health problems for living organisms. In this work, we have developed an electrochemical sensor based on a strontium manganese oxide/functionalized hexagonal boron nitride (SrMnO3/f-BN) electrocatalyst for the detection of the antibiotic drug furaltadone (FLD). Various analytical techniques were used to characterize the physicochemical properties of the as-prepared SrMnO3/f-BN composite. The as-fabricated SrMnO3/f-BN composite electrode showed excellent sensing activity towards FLD, with a wide linear range (0.01–152.11 µM) and low detection limit (2.0 nM). The sensor exhibited good selectivity towards FLD for detection in the presence of various interfering species (nitro compounds, metal ions, and biological compounds). Interestingly, real-time analysis using the proposed SrMnO3/f-BN composite was able to determine the FLD content in human urine and wastewater samples with good recovery. Hence, the as-developed SrMnO3/f-BN modified sensor could be viable in practical applications to target the antibiotic drug FLD in both human fluids and environmental samples. [ABSTRACT FROM AUTHOR]

A hafnium strontium oxide (HfSrO) liquid crystal (LC) alignment film was efficiently created through brush coating, and its ability to change the LC alignment direction was confirmed. A brush was applied to HfSrO sol coated on an indium-tin oxide substrate, after which the coating was solidified at various curing temperatures. It was confirmed that a directional micro/nanostructure was formed above 280°C due to the shear stresses caused by the movement of the brush hairs. Surface chemical changes were analyzed by using X-ray photoelectron spectroscopy and contact angle measurements. As the curing temperature increased, the prevalence of oxygen bonds increased and the contact angle decreased, thereby increasing the surface energy. The anisotropic boundary of the microgrooves and the van der Waals forces due to an increase in surface energy changed the alignment direction of LC molecules from vertical to horizontal, as verified through polarized optical microscopy and pretilt angle measurements. Thus, the efficiency of the brush-coating method, which dramatically simplifies the LC alignment film process, was confirmed. The homeotropic/homogeneous LC alignment property of the HfSrO film produced through brush coating depending on the curing temperature provides an innovative approach for LC alignment. [ABSTRACT FROM AUTHOR]

In this study, strontium titanate (SrTiO 3) nanoparticles were obtained utilizing a one-step supercritical continuous solvothermal synthesis process involving acetylacetonate precursors for both strontium and titanium cations instead of the historical alkoxide ones. These precursors are expensive, difficult to access (especially for strontium isopropoxyde) and inadequately stable, forcing the use of a glove box and controlled atmospheres, which is not the case for acetylacetonates. Pure SrTiO 3 nanoparticles with a crystallite size of roughly 20 nm were successfully synthesized. In addition to the cubic structure of SrTiO 3 , FTIR revealed surface functions that are typical of "wet" processes, while Raman spectroscopy showed the activation of non-centrosymmetric modes brought on by non-linear contributions. The nanoparticles show a faceted shape and are stable at elevated temperatures (up to 800 °C), according to in-situ high temperature XRD measurements. However, due to a chemical deficiency in strontium, titanium dioxide (TiO 2) phases are formed at higher temperatures. In-situ high temperature HRTEM investigations showed the existence of two populations of particles, with a better stability for the bigger-sized particles after thermal treatment as well as the sintering and restructuring of the smallest ones. Also, the microscopy results suggest the possibility of a chemical inhomogeneity within the crystallites. Overall, this study offers important new knowledge on the physicochemical characteristics of the synthesized SrTiO 3 nanoparticles and their thermal stability using a novel supercritical continuous solvothermal approach based on the use of acetylacetonate precursors. [Display omitted] • Strontium titanate (SrTiO 3) is a fascinating material for "green" applications. • A new and simple supercritical solvothermal flow synthesis using acetylacetonate precursors. • Unique metastable nanoparticles of strontium titanate with unusual thermal stability. • In-situ TEM investigation of metastable nanoparticles of strontium titanate evolution. [ABSTRACT FROM AUTHOR]

Perovskite ceramic oxides (ABO 3) have emerged as strong contenders against graphite anodes in non-aqueous metal-ion batteries. Exploring perovskites, we studied lithium insertion in barium lead oxide (BaPbO 3) and strontium lead oxide (SrPbO 3) perovskites, where lead (Pb4+) occupies the B-site. BaPbO 3 and SrPbO 3 , mass produced by solid-state or solution-combustion route, delivered reversible capacities upto 333 mAh/g and 339 mAh/g corresponding to 4.3 and 4.9 lithium uptake, respectively at room temperature. Among them, BaPbO 3 showed stable cycling for 50 cycles. Furthermore, at 50 ⁰C, BaPbO 3 delivers a first charge capacity of 382 mAh/g (or 5.6 lithium per formula unit) maintaining excellent stability beyond 50 cycles. Ex situ diffraction and microscopy studies confirm charge storage occurs via initial conversion (PbIV/PbII → Pb0) followed by reversible (de)alloying (Li–Pb) reaction. These results showcase perovskites as a promising family of Li-ion battery anodes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Photoluminescent and photochromic transparent composite adhesive was developed. • Lanthanide aluminate (8–13 nm) was immobilized in CMC-reinforced gum Arabic. • Smart luminous adhesive showed high photostability and superhydrophobicity. • Emission band was detected at 519 nm upon excitation at 365 nm. • Ultraviolet-driven photochromism was detected from transparent to green. Smart polymer glue with photoluminescence and water-repellent properties was developed. The luminescent adhesive continues emitting light for up to 120 min after turning the excitation source off. Nanoparticles of lanthanide strontium aluminum oxide (LSAO) (8–13 nm) were consistently immobilized into carboxymethyl cellulose-reinforced gum Arabic (CMC/GA) adhesive. Using various concentrations of LSAO, the generated adhesives showed emission intensity at 519 nm and an excitation band at 365 nm. Depending on LSAO content, both of afterglow and fluorescence emission were monitored. Photochromism was detected as the transparent adhesive film changes color to green under ultraviolet irradiation. A greenish-yellow lightening in a darkened place was also observed. The nanocomposite resistance to scratches and hydrophobicity were found to enhance as the LSAO content was increased in the carboxymethyl cellulose-reinforced gum Arabic matrix. The LSAO@CMC/GA nanocomposite showed high durability and photostability. The present strategy proved the viability of a potential mass production toward photoluminescent adhesives for various smart applications, such as smart packaging, anti-counterfeiting printing, smart windows, and safety signs. [ABSTRACT FROM AUTHOR]

Photochromic wood materials are very important and appealing for smart windows. Herein, we describe the development of transparent photochromic wood that can change its color under ultraviolet and visible lights. Photoluminescent transparent wood was prepared by delignification of wood followed by infiltration with a combination of gum Arabic/chitosan/acrylic acid (ACA), lanthanide-activated aluminum strontium oxide (LASO) as a photoluminescent, and Genipin as a cross-linking agent. The produced mixture was then infused into the lignin-modified wood substrate. In order to develop a luminescent colorless wood, the LASO phosphor must be well-distributed in the ACA solution without aggregation. According to the colorimetric parameters and photoluminescence spectra, this optically active wooden window switched color from transparent in daylight to green when UV-irradiated. Transmission electron microscopy (TEM) was employed to examine the morphological features of phosphor nanoparticles. The morphological features of the developed smart wooden window were investigated by scanning electron microscopy (SEM), X-ray fluorescent spectroscopy (XRF), and energy-dispersive X-ray analyzer (EDX). The mechanical performance was explored by investigating both hardness and resistance to scratches. The luminescent woods displayed an emission band at 518 nm when excited at 365 nm. The superhydrophobic performance and ultraviolet shielding of woods were improved upon increasing the phosphor content. [ABSTRACT FROM AUTHOR]

Polymeric films made from chitosan (CS) doped with metal oxide (MO = cobalt (II) oxide and strontium oxide) nanoparticles at different concentrations (5, 10, 15, and 20% wt. MO/CS) were fabricated with the solution cast method. FTIR, SEM, and XRD spectra were used to study the structural features of those nanocomposite films. The FTIR spectra of chitosan showed the main characteristic peaks that are usually present, but they were shifted considerably by the chemical interaction with metal oxides. FTIR analysis of the hybrid chitosan-CoO nanocomposite exhibited notable peaks at 558 and 681 cm−1. Conversely, the FTIR analysis of the chitosan-SrO composite displayed peaks at 733.23 cm−1, 810.10 cm−1, and 856.39 cm−1, which can be attributed to the bending vibrations of Co-O and Sr-O bonds, respectively. In addition, the SEM graphs showed a noticeable morphological change on the surface of chitosan, which may be due to surface adsorption with metal oxide nanoparticles. The XRD pattern also revealed a clear change in the crystallinity of chitosan when it is in contact with metal oxide nanoparticles. The presence of characteristic signals for cobalt (Co) and strontium (Sr) are clearly shown in the EDX examinations, providing convincing evidence for their incorporation into the chitosan matrix. Moreover, the stability of the nanoparticle-chitosan coordinated bonding was verified from the accurate and broadly parametrized semi-empirical tight-binding quantum chemistry calculation. This leads to the determination of the structures’ chemical hardness as estimated from the frontier’s orbital calculations. We characterized the dielectric properties in terms of the real and imaginary dielectric permittivity as a function of frequency. Dielectric findings reveal the existence of extensive interactions of CoO and SrO, more pronounced for SrO, with the functional groups of CS through coordination bonding. This induces the charge transfer of the complexes between CoO and SrO and the CS chains and a decrease in the amount of the crystalline phase, as verified from the XRD patterns.

The aim of this experiment was to determine the effect of the addition of strontium oxide on the recrystallization of zirconium silicate when adding strontium oxide to the glaze composition. Zirconia glazes (four different contents) were prepared, to which strontium oxide was added in amounts of 0, 1, 3, 6, and 12 mass% SrO. The characteristic temperatures of the raw glazes were measured, based on which the maximum firing temperatures were determined. The fired glazes were subjected to a study of their phase compositions and an observation of their microstructures. An analysis of the characteristic temperatures showed a fluxing effect, but it was not as strong for all glazes. Differences in the amount of the crystalline phase of zirconium silicate obtained in the fired glazes, as well as the partial transition of zirconium silicate to the amorphous phase, were observed. Observations of the microstructure clearly indicated an increase in the homogeneity of the distribution of zirconium silicate.

A chemical co-precipitation route was used to synthesize novel strontium oxide (SrO), SrO-starch composite and various tellurium (Te) concentrations were incorporated in SrO-starch composite. This study aims to enhance the catalytic activities and bactericidal behavior of SrO, SrO-starch composite with different percentage concentrations of Te doping and a fixed amount of starch nanoparticles. XRD affirmed that the dopant contribution was investigated to improve crystallinity. Surface morphological characteristics and elemental composition evaluation were determined using an FE-SEM and EDS exhibit a doping concentration of an element in the synthesized products. The configuration of Sr–O–Sr bonds and molecular vibrations has been indicated by FTIR spectra. In addition, dye degradation of prepared samples was investigated through catalytic activity (CA) in the existence of NaBH 4 act as a reduction representative. The Te-doped SrO-starch composite indicates superior catalytic activity and shows a degradation of Methylene blue dye (91.4 %) in an acidic medium. The synthesis nanocatalyst demonstrated impressive antibacterial activity against Staphylococcus aureus (S. aureus) at high and low concentrations exhibiting zones of inhibition 9.30 mm as compared to ciprofloxacin. Furthermore, molecular docking studies of synthesized nanocomposites were performed against selected enzyme targets, i.e., β -lactamase E.coli and DNA Gyrase E.coli. [ABSTRACT FROM AUTHOR]

The features of the process of glycol-citrate synthesis of highly dispersed oxide La0.6Sr0.4Co0.2Fe0.8O3 – δ with varying concentrations of the oxidizing agent (nitro group) and reducing agent (ethylene glycol) in the reaction system have been studied. The effect of the parameters indicated on the thermal behavior, spectral characteristics, phase composition, and microstructure of the obtained nanopowders has been determined. It is shown that the proposed synthesis conditions make it possible to reduce the formation temperature of single-phase highly dispersed oxides of a given composition, which are promising as cathode materials for medium-temperature solid oxide fuel cells. [ABSTRACT FROM AUTHOR]

Novel Au and cellulose nanocrystals (CNC)-doped SrO nanocomposites have been fabricated using simple and cost-effective chemical co-precipitation technique. Various concentrations of Au were doped into fixed amounts of CNC and SrO nanocomposites. The objective of this triplex nanocomposite was to examine the effect of incorporating dopants in SrO on the efficient elimination of organic contaminants from water and their antibacterial potential with molecular docking study. Adequate experimental conditions such as temperature, suitable volume ratio of reactants and pH were generated during the synthesis. For comparative studies, nanocomposites were evaluated through a number of characterization tools. The structural and morphological analysis through XRD and HR-TEM revealed the cubic crystalline structure of aggregated SrO quantum dots (QDs). Furthermore, an interconnected chain-like structure of nanoclusters was observed upon CNC and Au incorporation in SrO lattice. The size of nanoclusters/nanoparticles was calculated to be approximately 30 nm which matched well with the reported literature. Reduction in crystallinity and bandgap from 4.12 eV (for pristine SrO) to 3.8 eV was observed upon co-doping with CNC and Au in SrO lattice. Furthermore, pH-based catalytic analysis of prepared nanocomposites revealed 98% dye degradation (in acidic media) against methylene blue ciprofloxacin (MBCF) dye along with good bactericidal activities against Gram-positive/negative bacteria, respectively. In silico molecular docking analysis for enzyme targets belonging to cell wall synthesis (penicillin-binding protein 4) and fatty acid synthesis (enoyl-[acyl-carrier-protein] reductase) suggested Au–CNC and Au/CNC-doped SrO nanostructures as possible inhibitors of these enzymes owing to their good binding scores and binding interactions with active site residues. (a) Preparation of cellulose nanocrystals (CNC) by acid hydrolysis. (b) Schematic synthesis route to fabricate Au/CNC–SrO nanocomposites. [ABSTRACT FROM AUTHOR]

We propose an efficient alignment method for liquid crystals (LCs). A brush-coating method handles film deposition and LC alignment treatment simultaneously herein, meaning a reduction in the conventional alignment layer treatment process steps. A lanthanum yttrium strontium oxide (LaYSrO) film prepared by the sol–gel process was used for the alignment layer. Topographical details of the brush-coated LaYSrO films (compared with spin-coated films) were investigated by atomic force microscopy. Spin-coated LaYSrO meant that the film formation alone without orientation treatment represented an isotropic surface. On the other hand, the 270 °C-cured brush-coated LaYSrO showed nano/microstructure with directionality. It indicates that brush-hair sweeping induced shearing stress on the sol state of the LaYSrO, which results in surface anisotropy for LC alignment. The uniform LC alignment state was confirmed by polarized optical microscopy and pretilt analysis. The brush-coated LaYSrO shows fine optical transparency compared to plain and indium-tin-oxide coated glasses, and thermal stability up to 150 °C for LC alignment. Competitive electro-optical performances of the brush-coated LaYSrO were verified in a twisted-nematic LC system compared to those of the conventionally used polyimide layer. Consequently, we expect that the brush-coating process can be an innovative technology for LC alignment. [ABSTRACT FROM AUTHOR]

Considering the high melting point and high stability of SrO, it has potential applications in the field of the preparation of titanium alloys. To improve the hydration resistance, SrO samples with different ZrO2 additions were fabricated after firing at 1 750 t for 6 h. The phase, the microstructure, and the hydration resistance of the samples were researched. The results show that the sample with 33 moP/o ZrO2 addition possesses good hydration resistance with the mass gain after hydration for 13 days of less than 0.42 mass°/o. The SrO crucible with 33 moP/o ZrO2 addition does not react with TiNi alloy melt during melting, which provides a support for searching new refractories with good hydration resistance for induction melting titanium alloys. [ABSTRACT FROM AUTHOR]

Catalytic co-pyrolysis (CCP) of ironbark (IB) and waste cooking oil (WCO) over bimetallic (Ni, Cu, Zn, Ag, and Fe) strontium oxide (SrO)-loaded hierarchical Y-zeolite was performed using Py-GC/MS. The effect of bimetallic catalyst on kinetics, reaction mechanisms and product distribution of CCP was examined. The bimetallic catalysts were prepared via wet impregnation and characterized using N2 adsorption-desorption, SEM, XPS and FTIR. CCP using Ag–SrO/Y-zeolite showed the lowest activation energy of 163.1 kJ/mol compared to non-catalytic co-pyrolysis (193.21 kJ/mol). The results indicated that Cu–SrO/Y-zeolite produced the highest aromatic yield of 65.43% at a temperature of 750 °C with a catalyst to feedstock ratio of 1:1. The present work indicates that Cu–SrO/Y-zeolite active sites increased the aromatic yield. [Display omitted] • Cu–SrO/Y-zeolite showed the highest mesoporous area and lowest activation energy. • Basic sites on X–SrO/Y-zeolite impact notably on ketonization of carboxylic acids. • Cu–SrO/Y-zeolite catalyst produced the highest aromatic yield of 65.43% at 750 °C. [ABSTRACT FROM AUTHOR]

The recent research on bioactive glasses (BGs) has mainly moved on two fronts: (1) introducing ions of therapeutic interest in their composition and (2) the development of scaffolds, fibers, coatings and sintered products starting from BGs in powder form. In this case, the main obstacle to overcome is that BGs rapidly crystallize during heat treatments, thus transforming into glass-ceramics with low reactivity, slow ion release and, eventually, poor mechanical properties. Here an innovative bioactive glass (BGMS_LS), capable of responding to the main limitations of commercial BGs, is presented. The new material contains strontium and magnesium, whose therapeutic relevance is well known, and can be sintered at extraordinarily low temperatures without crystallizing, thus keeping all of its biological potential intact. [ABSTRACT FROM AUTHOR]

This study presents results on the development of strontium oxide (SrO) containing glass sealants used to join Crofer22APU to yttria-stabilized zirconia (3YSZ), in which the main glass components, that is, silicon oxide (SiO2), strontium oxide (SrO), calcium oxide (CaO) and aluminum oxide (Al2O3), have been varied appropriately. Certain properties, such as the crystallization behavior, the coefficient of thermal expansion, adhesion, and reactivity of the sealants in contact with Crofer22APU, have been reviewed and discussed. The optimized glass composition (with CTE in the 9.8–10.3 × 10−6 K−1 range) results in a good joining behavior by hindering the formation of undesirable strontium chromate (SrCrO4) on contact with the Crofer22APU steel after 1000 h. at 850 °C. High specific resistivity values of about 106 Ohm.cm have been obtained, thus demonstrating good insulating properties at 850 °C under an applied voltage of 1.6 V. A negligible degradation in the electrical resistivity trend was measured during the test up to 1000 h, thus excluding the presence of detrimental reactions of the glass-ceramic sealant in contact with Crofer22APU under a dual atmosphere, as confirmed using SEM-EDS post-mortem analyses. [ABSTRACT FROM AUTHOR]

Summary: The transesterification of waste oils to biodiesel was carried out in the presence and absence of ultrasound. A new nanocatalyst of the calcium‐strontium oxide was applied with high catalytic activity. The innovation of this work is an environmentally friendly synthesized nanocatalyst with ultrasound at low temperatures. After synthesis, the nanocatalyst was characterized with FESEM, FT‐IR, and CO2‐TPD, NH3‐TPD. It was mesoporous and showed great basicity by the CO2‐TPD method. The highest conversion of biodiesel was 99.2% under optimal reaction conditions (2.5 wt% nanocatalyst, oil to methanol molar ratio 1:6, time 40 minutes, temperature 35°C, and 42% amplitude of ultrasound). 1HNMR, FTIR, and GC‐FID tracked the characterization of biodiesel. The physical and fuel properties of biodiesel were evaluated according to the ASTM standardized method. Based on a kinetic study, the activation energy in the mechanical agitation method was about twice as high as in the ultrasonic method. A high turnover frequency and low environmental factors indicate that biodiesel synthesis from waste oil with this nanocatalyst is fast, efficient, and effective in the environment. Biodiesel was synthesized using calcium‐strontium oxide nanocatalyst, waste oil, and ultrasonic in a green and eco‐friendly process with time and cost savings. Highlights: Calcium‐strontium oxide is a novel super base nanocatalyst synthesized for transesterification.The highest biodiesel yield achieves 99.2 wt% from this green synthesis with a low E‐factor.The reaction followed the pseudo‐first‐order kinetics model.The turnover frequency of nanocatalyst is suitable for an industrial application.The calcium strontium oxide has proper reusability up to the six‐run. [ABSTRACT FROM AUTHOR]

Recently, Strontium oxide (SrO) nanoparticles (NPs) and hybrids outperformed older commercial catalysts in terms of catalytic performance. Herein, we present a microwave-assisted easy in situ solution casting approach for the manufacture of strontium oxide nanoparticles doped within a naturally occurring polymer, chitosan (CS), at varying weight percentages (2.5, 5, 10, 15, and 20 wt.% SrO/chitosan). To construct the new hybrid material as a thin film, the produced nanocomposite solutions were cast in petri dishes. The aim of the research was to synthesize these hybrid nanocomposites, characterize them, and evaluate their catalytic potential in a variety of organic processes. The strontium oxide-chitosan nanocomposites were characterized using Fourier transform infrared (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM) techniques. All the results confirmed the formation of chitosan–strontium oxide nanocomposite. FTIR spectrum of nanocomposite showed the presence of a characteristic peak of Sr-O bond. Furthermore, XRD revealed that SrO treatment increased the crystallinity of chitosan. The particle size was calculated using the Debye–Scherrer formula, and it was determined to be around 36 nm. The CS-SrO nanocomposite has been proven to be a highly efficient base promoter for the synthesis of 2-hydrazono [1,3,4]thiadiazole derivatives. To optimize the catalytic method, the reaction factors were investigated. The approach has various advantages, including higher reaction yields, shorter reaction durations, and milder reaction conditions, as well as the catalyst's reusability for several applications. [ABSTRACT FROM AUTHOR]

Textiles that respond to external stimuli with a change in their properties are referred to as "smart clothing". Fluorescent textiles, which change color in response to light, are a subset of smart textiles. Herein, fluorescent and hydrophobic composite coatings were prepared and applied onto cellulose-based fabrics by the pad-dry-curing method. This innovative approach involves the integration of lanthanide-doped aluminum strontium oxide pigment phosphor nanoparticles into room temperature vulcanized silicone rubber. The pigment phosphor nanoparticles must be uniformly dispersed without agglomeration in order to create a transparent nanocomposite film. The pad-dry-cured film was successfully cured onto the cotton fabric under ambient conditions. The superhydrophobic activity of the fluorescent fibers improved with increasing pigment content. Both the ultraviolet protection and the antibacterial properties of the coated fibers were also investigated. The generated translucent fluorescent layer exhibited an absorbance peak of 358 nm and an emission peak of 517 nm. The fluorescent cotton fibers exhibited different colors, including white under visible daylight and intense green under ultraviolet devices, as described by the CIE Lab, as well as decay time, excitation and emission spectra. Both the mechanical performance and comfortability of the coated fibers were tested by measuring air permeability and bend length. The spectroscopic results of the treated fabrics are detailed using a scanning electron microscope and energy dispersive X-ray spectra. During ultraviolet stimulation, the coated cloth displayed a reversible and fast fluorescent photochromism that was not fatigued. The qualities of colorfastness were described, including washing, crocking, sweat, and light. [ABSTRACT FROM AUTHOR]

Thermal treatment of a 0.52SiO2-0.24SrO-0.24 -x Na2O- x MO glass-ceramic series (where x = 0.08 and MO = Y2O3 or CeO2) was conducted in order to synthesize yttrium (Y3+) and cerium (Ce3+) crystalline species that may act as radical oxygen specie (ROS) scavengers. The prominent phase for the Control is a sodium-strontium-silicate while the experimental glass-ceramics (HY, YCe, and HCe) present sodium-Y/Ce-silicate and oxide phases. Disk shrinkage during thermal processing ranges from 1–7% for Control, HY, YCe, and HCe in both diameter and thickness. Solubility studies determined that the release of Si4+ and Na+ are greatest from the Control disks which peaks at 1550 µg/mL. Release from the Y3+ and Ce3+ glass-ceramics reached 320 µg/mL for Si4+ and 630 µg/mL for Na+. The range of antioxidant capacity (ABTS assay) for all samples was 0.31–3.9 mMTE. No significant reduction in MC 3T3 Osteoblast cell viability was observed for any composition tested. [ABSTRACT FROM AUTHOR]

Summary: This study was conducted to improve the stability of a high‐performance cathode, which plays a crucial role in lowering the operating temperature of solid oxide fuel cells (SOFCs) to below 600°C while retaining its performance. Lanthanum strontium cobalt oxide (LSC) is a representative SOFC cathode material used in the intermediate temperature (IT) region (500°C‐600°C). When segregation occurs on the cathode surface during high‐temperature fabrication, the initial performance degrades to a certain extent, followed by continuous performance degradation. Herein, we aimed to overcome this degradation through surface modification. Accordingly, an ideal LSC surface composition was achieved by removing the segregated Sr through wet chemical etching of the cathode surface. Further, an atomic layer deposition (ALD) process of less than 1 nm thickness was introduced to prevent further Sr separation and minimize performance degradation. The peak power density of the cell with the modified surface (M‐LSC) at 550°C was 509 mW cm−2, whereas that of the cell with bare LSC was 483 mW cm−2. Based on the 70‐h short‐term stability test, the bare LSC showed a degradation of 70 mV, while the M‐LSC remained stable with no degradation. [ABSTRACT FROM AUTHOR]

Strontium cobalt oxide is an important perovskite‐type material in the research of solid oxide fuel cells (SOFCs), since a great number of derived cathode materials can be obtained through composition modification against SrCoO3‐δ (SCO). In this work, pristine SCO without any additional dopants was synthesized, and its electrochemical properties were evaluated according to the electrochemical impedance spectroscopies (EIS) analyses through the distribution of relaxation times (DRT) method on the symmetrical cells. The undoped SCO displayed low polarization resistances as well as a high oxygen transport ability, even comparable to the famous cathode, Sm0.5Sr0.5CoO3‐δ (SSC). Oxygen surface and bulk diffusion were found to be the dominating processes in the oxygen reduction reaction (ORR) of SCO. These results could broaden our knowledge about the ionic transport behavior of SCO‐based perovskite materials. [ABSTRACT FROM AUTHOR]

The production of strontium oxide nanoparticles from an aquatic plant extract is described here. UV–vis spectroscopy at ~ 220 nm was used to confirm the biosynthesis of these particles, and the color of the mixtures altered from colorless to green. The morphology of Elodea canadensis strontium oxide nanoparticles (EcSrONPs) was characterized using FE-SEM. FE-SEM images demonstrated that these particles adopted disordered, irregular shapes with agglomeration and slightly smooth surfaces. FE-TEM confirmed the results of FE-SEM analysis. These particles were also evaluated using XRD, XPS, and FTIR. The XRD pattern revealed a face-centered cubic crystalline structure at (209) and (217), while the XPS results verified the presence of both strontium and oxygen in the synthesized EcSrONPs. FTIR results confirmed that phytochemical functional groups served as capping agents during EcSrONP synthesis. In addition, zeta potential analysis confirmed the stability of EcSrONPs. Finally, the antibacterial potential of the produced EcSrONPs against Escherichia coli and Bacillus subtilis was evaluated. The largest inhibitory zone against E. coli (diameter, 22 mm) and B. subtilis (diameter, 20 mm) was observed at a EcSrONPs concentration of 24 µg·mL−1. Collectively, the findings of this research show that the biosynthesis of EcSrONPs is a viable option for developing novel materials for biomedical applications. [ABSTRACT FROM AUTHOR]

In this work, we performed a first-principles calculation to investigate the effect of intrinsic defects on the electronic structure and magnetic properties of SrO crystals in detail. The calculated results show that intrinsic defects do not cause obvious lattice distortion and they can introduce impurity energy levels in the forbidden band of SrO crystals. The defect states originate from O-2p or Sr-4d states, which may become electron (hole) trapping centers or form an acceptor level in the forbidden band. However, different defects induce different magnetic moments. The magnetic moments of SrO with Vsr, Osr, SrO and Oi are 1.85 μB, 3.11 μB, 1.64 μB and 1.68 μB, respectively, while VO and Sri do not lead to a magnetic moment in the SrO crystal. It is found that the magnetic moment mainly arises from the spin polarization of O-2p and Sr-4d orbital electrons of defective atoms and their nearest neighbor atoms. Without considering Vsr here, Osr and Oi are the most stable defects in the SrO crystal under O-rich conditions while VO is the most stable defects under Sr-rich conditions. We suggest that the magnetism in SrO with intrinsic defects most likely originate from Osr and Oi. [ABSTRACT FROM AUTHOR]

In general, n-type thermoelectric materials are rather difficult to design. This study particularly pivoted on designing potential environmentally benign oxides based n-type thermoelectric material. We synthesized Sr2CoMoO6 (SCMO) polycrystalline ceramics via the solid-state synthesis route. XRD, SEM, and thermoelectric measurements were carried out for phase constitution, microstructure analysis, and to determine its potential for thermoelectric applications. As-sintered SCMO sample showed an insulator like behavior till 640 °C after which it exhibited an n-type non-degenerate semiconductor behavior followed by a p-n type conduction switching. To stabilize a high temperature n-type behavior, annealing of SCMO in reducing atmosphere (H2) at 1000 °C was carried out. After annealing, the SCMO demonstrated an n-type semiconductor behavior throughout the temperature range of measurement. The electrical conductivity (σ) and the power factor (S2σ) were found to be increased manifold in the annealed SCMO double perovskite. [ABSTRACT FROM AUTHOR]

The control of thin film stoichiometry is of primary relevance to achieve desired functionality. Pulsed laser deposition ablating from binary-oxide targets (sequential deposition) can be applied to precisely control the film composition, offsetting the importance of growth conditions on the film stoichiometry. In this work, we demonstrate that the cation stoichiometry of SrTiO3 thin films can be finely tuned by sequential deposition from SrO and TiO2 targets. Homoepitaxial SrTiO3 films were deposited at different substrate temperatures and Ti/Sr pulse ratios, allowing the establishment of a growth window for stoichiometric SrTiO3. The growth kinetics and nucleation processes were studied by reflection high-energy electron diffraction and atomic force microscopy, providing information about the growth mode and the degree of off-stoichiometry. At the optimal (stoichiometric) growth conditions, films exhibit atomically flat surfaces, whereas off-stoichiometry is accommodated by crystal defects, 3D islands, and/or surface precipitates depending on the substrate temperature and the excess cation. This technique opens the way to precisely control stoichiometry and doping of oxide thin films. [ABSTRACT FROM AUTHOR]

The redesigned engineering building of nanocomposite (NCP) depends on metal oxides of palladium oxide (PdO) nanoparticles (NPs) conjugate with the n-type semiconductor of strontium oxide (SrO) NPs on the electron carrier surface of graphene oxide (GO) and reduce graphene oxide (rGO) nanosheet is the main target of the current work. The low efficiency of PdO (n-type) and SrO (p-type) gave an overview of the increasing generation electron efficiency via building the ohmic area on the GO and rGO surface using the Z-scheme mechanism. The efficiency of the NCP surface for destroying organic pollutants such as mixed dyes of Rhodamine B and methylene blue (RhB/MB), as against insecticides like imidacloprid, and the removal of heavy metals such as chromium ions was studied. The production of clean water against pollutants materials was investigated through adsorption and photocatalytic processes, electrochemical, and spectroscopy methods to detect the activity of NCP. The rate constant of the adsorption pollutants is 0.1776 min−1 (MB), 0.3489 min−1 (RhB), 0.3627 min−1 (imidacloprid), and 0.5729 min−1 (Cr3+). The photocatalytic rate recorded at 0.01218 min−1 (MB), 0.0096 min−1 (RhB), appeared degradation rate at 0.0086 min−1 (imidacloprid), 0.0019 min−1 (Cr6+), and 0.0471 min−1 (Cr3+). The adsorption and photocatalytic efficiency of nanocatalyst (NCP) was calculated at 91% (RhB), 93% (MB), 73% (imidacloprid), 63% (Cr3+), while the photocatalytic efficiency is 63% (RhB), 94% (MB), 86% (imidacloprid), 33% (Cr3+). The recyclability of NCP was tested for five cycles, and the efficiency was discovered at 55% after the fifth cycle. The cytotoxicity of NCP was studied to detect the safety of the fabricated materials. The study validates that the fabricated nanocomposite exhibits great potential as an innovative material for producing clean water. [Display omitted] • Design of nano-catalyst of palladium and strontium oxides depends on n/p-heterojunction. • High-ability surface for destroying organic contaminats and heavy metals. • Efficient adsorption and photocatalytic for removal of pollutants. • Spectroscopy and electrochemical techniques to detect the nanocatalyst efficiency. • High-efficiency catalyst after fifth recycling and safe for water treatment. [ABSTRACT FROM AUTHOR]

Magnetically frustrated lattices even at low temperatures are well-known for not minimizing interaction energies. In a magnetically frustrated structure like strontium gadolinium oxide (SrGd2O4), there exists more than one suitable site for rare-earth doping due to availability of two low Gd3+ site symmetries. In the present work SrGd2O4 doped with Eu3+ ions were prepared by solid-state reaction method. Structural characterization confirms the nature of structure and bonding. Existence of different sites in the host lattice for the doped Eu3+ ions were observed via excitation spectra. Photoluminescence studies with varying temperature (15–300 K) have been extensively used with high-resolution to distinguish different sites in this structure. Studies confirm that apart of the Gd3+ sites, Sr2+ could also accommodate the Eu3+ ions. Variation of temperature that leads to shift in emission spectral peak positions has been thoroughly examined for line shift temperature sensing applicability. Low temperature uncovers emission peaks from 5D1 level that are unprovable at room temperature. Maximum relative sensitivity of 5D0 → 7F0 peak intensity to one of the multiple sites in SrGd2O4:Eu3+ has been found to be 12.08 × 10–3% K−1 while using McCumber-Sturge equation to quantify line shift. [ABSTRACT FROM AUTHOR]

Magnetically frustrated lattices even at low temperatures are well-known for not minimizing interaction energies. In a magnetically frustrated structure like strontium gadolinium oxide (SrGd2O4), there exists more than one suitable site for rare-earth doping due to availability of two low Gd3+ site symmetries. In the present work SrGd2O4 doped with Eu3+ ions were prepared by solid-state reaction method. Structural characterization confirms the nature of structure and bonding. Existence of different sites in the host lattice for the doped Eu3+ ions were observed via excitation spectra. Photoluminescence studies with varying temperature (15–300 K) have been extensively used with high-resolution to distinguish different sites in this structure. Studies confirm that apart of the Gd3+ sites, Sr2+ could also accommodate the Eu3+ ions. Variation of temperature that leads to shift in emission spectral peak positions has been thoroughly examined for line shift temperature sensing applicability. Low temperature uncovers emission peaks from 5D1 level that are unprovable at room temperature. Maximum relative sensitivity of 5D0 → 7F0 peak intensity to one of the multiple sites in SrGd2O4:Eu3+ has been found to be 12.08 × 10–3% K−1 while using McCumber-Sturge equation to quantify line shift. [ABSTRACT FROM AUTHOR]

Since the discovery of 1970s, bioactive glass has been a hot topic of research because of its excellent biological activity, which makes it a material that can repair and replace human bone tissue organs. In this work, the bioactive glasses in the system SiO 2 –P 2 O 5 –Na 2 O–CaO–F with different amounts of strontium oxide (SrO) and zinc oxide (ZnO) were prepared by the conventional melt quenching technology. The hydroxyapatite (HA) forming ability, ion release and antibacterial activity of these prepared glasses were investigated and the obtained results illustrated that SrO-doped samples had a better ability to form HA in modified simulated body fluid (MSBF) than ZnO-doped samples. As the immersion time of the sample in MSBF increased, the content of HA phase gradually increased. In the same immersion time, the formation ability of HA and the variation of SrO substitution amount showed a non-linear trend, which is mainly related to the influence of SrO content on the glass network structure. The results of ion concentration showed that the formation of HA was the result of the comprehensive action of various ions in the solution, especially the release rate of Si4+ ions, which had a direct impact on the formation ability of HA. The antibacterial test illustrated that the difference in antibacterial activity of bacteria solution at different sample concentrations may be related to the high pH environment and the osmotic effects caused by the non-physiological concentration of ions in the solution. The glass sample contained 4 wt% SrO showed the minimum bactericidal concentration at 64 mg/mL. The glass samples prepared in this experiment had good biological activity and antibacterial effect, making them suitable for using in dentistry and orthopedic applications, as well as providing a valuable composition reference for the preparation of bioactive glass with excellent comprehensive properties. [ABSTRACT FROM AUTHOR]

To electrochemically control structural and transport properties of oxygen-deficient perovskite SrFeOy (2.5 ≦ y ≦ 3) (SFO) epitaxial films, we employed electric-field-effect transistor structures in which the proton-conducting solid electrolyte Nafion is used as a gate insulator. When a positive gate voltage (VGS) is applied and protons are injected toward the film channel layer, the SFO films are electrochemically reduced, leading to increases in the channel resistance. On the other hand, when a negative VGS is applied and protons are removed, the SFO films are oxidized, and as a result, the channel resistances decrease. In addition, we found that the electrochemically reduced SFO films accommodate protons, forming the proton-containing oxide HxSrFeO2.5 whose proton concentration is determined by elastic recoil detection analysis to be x ∼ 0.11. Our results indicate the usefulness of the proton-conducting solid electrolyte for electrochemically controlling transition metal oxides and for exploring proton-containing oxides. [ABSTRACT FROM AUTHOR]

Integration of metal‐organic frameworks (MOFs) as components of advanced electronic devices is at a very early phase of development and the fundamental issues related to their crystal growth on conductive substrate need to be addressed. Herein, we report on the structural characterization of a newly synthesized Sr‐based MOF {[Sr(2,5‐Pzdc)(H2O)2] ⋅ 3 H2O}n (1) and the uniform crystal growth of compound 1 on a conducting glass (fluorine doped tin oxide (FTO)) substrate using electrochemical deposition techniques. The Sr‐based MOF 1 was synthesized by the reaction of Sr(NO3)2 with 2,5‐pyrazinedicarboxylic acid dihydrate (2,5‐Pzdc) under solvothermal conditions. A single‐crystal X‐ray diffraction analysis revealed that 1 has a 3D structure and crystallizes in the triclinic P1‾ space group. In addition, the uniform crystal growth of this MOF on a conducting glass (FTO) substrate was successfully achieved using electrochemical deposition techniques. Only a handful of MOFs have been reposed to grown on conductive surfaces, which makes this study an important focal point for future research on the applications of MOF‐based devices in microelectronics. [ABSTRACT FROM AUTHOR]

In this work kinetics of carbonation reaction of strontium oxide was investigated using the well-known random pore model. This non-catalytic gas-solid reaction can be utilized both for carbon capture and storage (CCS) and thermochemical energy storage (TCES) applications. In order to obtain kinetic parameters and reaction rate equation, a set of experiments ranging from 800 °C to 950 °C in temperature and 5 to 40 vol% in concentration of CO 2 were conducted. It was concluded that fractional function describes the concentration dependency of reaction rate very well. The activation energy of this reaction was calculated to be about 64 kJ/mol and the best exponential function indicating temperature dependency of CO 2 diffusivity through the product layer was also estimated. Furthermore, it was attempted to depict the importance of this reaction for CCS and TCES purposes. This goal was achieved by comparing our results with those of around 50 similar researches carried on MgO, CaO, and SrO-based sorbents. Comparison was done using six screening criteria; i.e. CO 2 uptake, CO 2 uptake rate, conversion, conversion rate, thermal energy, and thermal power. • Kinetics of SrO carbonation reaction is investigated by random pore model. • Energy storage parameters of SrO carbonation are compared with CaO and MgO. • Thermal storage efficiency of SrO is good due to its high release temperature. [ABSTRACT FROM AUTHOR]

In this research, the study of two dopants, strontium oxide and manganese oxide were thoroughly investigated based on the elastic properties for the purpose of high strength glass application. The melt quenching technique method was used to synthesize two series of borotellurite glass systems doped with manganese and strontium. Elastic measurement, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the prepared glass samples. The increment of molar volume confirmed the theory that molar volume is inversely proportional to the density parameters. A broad hump was observed during XRD as the samples shows pure amorphous nature. In FTIR, the vibrations of the functional group of the tellurite network were recorded such as TeO4 trigonal bipyramids and TeO3 trigonal pyramids, by addition of both dopants. On the other hand, ultrasonic velocity was used to determine the elastic moduli of the glass such as bulk modulus, shear modulus, longitudinal modulus, Young's Modulus, microhardness and Poisson's ratio which showed decreasing and increasing trends with the increased concentration of MnO2 and SrO respectively. It is also inferred that strontium oxide has better elastic properties than manganese oxide. [ABSTRACT FROM AUTHOR]

Barium strontium oxide-coated carbon nanotubes (CNTs) were implemented as a work function lowering and field enhancing functional coating on a coiled tungsten filament to create a new thermionic cathode. This cathode resembles conventional oxide cathodes in structure. It has the same coiled tungsten filament as a conventional oxide cathode but uses barium strontium oxide-coated CNTs instead of the traditional barium strontium calcium oxide powder mixture as an emissive coating. The cathode produces a strong thermionic emission. At 1395 K and 2.5 V/μm, the thermionic emission current of 0.87 A or current density of 2.9 A/cm2 was obtained from this oxide-coated CNT cathode. This level of emission is about three times as large as a conventional oxide cathode operating at similar temperature and field strength. Strong thermionic emissions from the cathode also lead to a large thermionic cooling effect. Temperature reduction as large as 90° was observed from the cathode surface when it was emitting electrons. Strong thermionic emission and a large cooling effect obtained are the result of the combination of the low work function of barium strontium oxide (1.6 eV) and the large field effect induced by the CNTs. Plasma enhanced chemical vapor deposition was used to grow CNTs, and magnetron sputtering deposition was used to deposit the barium strontium oxide functional coating; details of the cathode fabrication are presented to illustrate both the versatility of the processing techniques and the adaptability of barium strontium oxide-coated CNTs as a functional coating. Measurements on thermionic emission and thermionic cooling of the cathode are also presented. [ABSTRACT FROM AUTHOR]

With the aim of developing new electronic functionalities for flexible devices, a transfer process for the preparation of flexible conductive thin films was examined using epitaxially grown anatase Nb: TiO2. Using pulsed laser deposition (PLD), water-soluble Sr3Al2O6 (SAO) was deposited on a single-crystalline LaAlO3 (100) substrate (LAO) as a sacrificial layer, followed by the epitaxial growth of anatase Nb: TiO2 on the sacrificial layer. The Nb: TiO2/SAO/LAO multilayer sample bonded onto a flexible polymer sheet via an adhesive tape was soaked into distilled water to transfer the epitaxially grown Nb: TiO2 thin film from SAO/LAO to the polymer sheet. The transferred anatase Nb: TiO2 thin film retained the clear X-ray diffraction peaks. Moreover, the areal transfer ratio was almost 100%, without the generation of significant impurity phases during the transfer process. On the basis of these results, the examined process was found promising for the preparation of flexible anatase Nb: TiO2 thin films. The voltage drop-current characteristics were measured successfully at room temperature for the transferred anatase Nb: TiO2 thin film using the standard four-probe method with gold electrodes. [ABSTRACT FROM AUTHOR]

Antiferromagnetic-paraelectric SrMnO3 (SMO) has aroused interest because of the theoretical strong coupling between the ferroelectric and ferromagnetic states with increasing epitaxial strain. In strained SMO films, the <110> polarized state and polar distortions have been observed, although high leakage currents and air degradation have limited their experimental verification. We herein provide a conclusive demonstration of room-temperature ferroelectricity and a high dielectric constant (εr = 138.1) in tensile-strained SMO by securing samples with insulating properties and clean surfaces using selective oxygen annealing. Furthermore, a paraelectricity and low dielectric constant (εr = 6.7) in the strain-relaxed SMO film have been identified as properties of the bulk SMO, which directly proves that the ferroelectricity of the tensile-strained SMO film is due to strain-induced polarization. We believe that these findings not only provide a cornerstone for exploring the physical properties of multiferroic SMO but also inspire new directions for single-phase multiferroics. Strain engineering: oxygen locks in room-temperature ferroelectricity Thin cracks and other defects which appear in multifunctional next-generation memory materials can be suppressed through a new synthetic technique. Compounds such as strontium manganese oxide (SrMnO3) transform from insulators into electrically and magnetically active materials when fabricated into thin films that strain the crystal's natural atom-atom separations. Sanghan Lee from the Gwangju Institute of Science and Technology, South Korea, and colleagues now report the first example of room-temperature electrical activity in strained SrMnO3 thin films. The team achieved this result by capping SrMnO3 with a layer of strontium ruthenium oxide (SrRuO3), and then annealing their new material in an oxygen-rich atmosphere. The team showed that the upper capping layer maintained the strained structure while also permitting oxygen to incorporate into the lower SrMnO3 film to eliminate vacancy defects. We provide a conclusive demonstration of strain-induced room-temperature ferroelectricity in SrMnO3 thin films by securing samples with insulating properties and clean surfaces using selective oxygen annealing. These findings will not only provide a cornerstone for exploring the physical properties of multiferroic SrMnO3 but will also inspire new directions for single-phase multiferroics. [ABSTRACT FROM AUTHOR]

The performance of Ni/SrO-doped CeO2 (SrDC) anode-supported cells, combined with the Sm2O3-doped CeO2 (SDC) electrolyte layer, has been investigated for the direct supply of a dry CH4. The SrO content in the Ce1-xSrxO2-x solid solution affects the porous structure of the starting anode support comprising of the sintered NiO and Ce1-xSrxO2-x grains and denseness of the SDC layer by co-sintering. The cell using the 5 mol% SrO-doped CeO2 shows the highest cell performance without time-dependent degradation even at 750°C. This cell (the 5SrDC cell) also provides better cell performance with decreasing operating temperature than the conventional Ni/YSZ anode-supported cell (the YSZ cell); the maximum power density of the 5SrDC cell is higher than that of the YSZ cell by 73% at 650°C. This enhancement effect is discussed in light of the mixed ionic-electronic conduction of the CeO2-based solid electrolytes. [ABSTRACT FROM AUTHOR]

First-principle calculations are used to model the adsorption and hydration of strontium bis(cyclopentadienyl) [Sr(Cp)2] on TiO2-terminated strontium titanate, SrTiO3 (STO), for the deposition of strontium oxide, SrO, by atomic layer deposition (ALD). The Sr(Cp)2 precursor is shown to adsorb on the TiO2-terminated surface, with the Sr atom assuming essentially the bulk position in STO. The C-Sr bonds are weaker than in the free molecule, with a Ti atom at the surface bonding to one of the C atoms in the cyclopentadienyl rings. The surface does not need to be hydrogenated for precursor adsorption. The calculations are compared with experimental observations for a related Sr cyclopentadienyl precursor, strontium bis(triisopropylcyclopentadienyl) [Sr(iPr3Cp)2], adsorbed on TiO2-terminated STO. High-resolution x-ray photoelectron spectroscopy and low-energy ion scattering spectroscopy show adsorption of the Sr precursor on the TiO2-terminated STO after a single precursor dose. This study suggests that ALD growth from the strontium precursors featuring cyclopentadienyl ligands, such as Sr(Cp)2, may initiate film growth on non-hydroxylated surfaces. [ABSTRACT FROM AUTHOR]

The growth behavior of pure and Sr included HfO2 composite thin films for different concentrations of Sr (5, 10, and 15 Wt%) through the Jet Nebulizer Spray Pyrolysis technique is discussed in detail. The preparation of Al/HfO2/n-Si and Al/Sr:HfO2/n-Si Schottky barrier diodes and their rectification behavior were compared. The appearance of intermediate (Sr2HfO4) and new (SrO2) phases upon introduction of Sr in HfO2 was recorded through XRD analysis, and particle size enlargement was observed. The absorption coefficients and bandgap energies of pure and Sr included HfO2 films were determined using UV-VIS analysis, and the results imply that the presence of Sr2HfO4 in Sr:HfO2 increases the overall bandgap from 3.8 to 4.0 eV. The morphology of pure HfO2 was heavily influenced by the presence of Sr; FESEM micrographs revealed that the self-assembled sphere like structure of HfO2 turned into mixed morphology like the rod shape of SrO2 and the contorted spheres of Sr2HfO4. EDAX elementary studies have confirmed the presence and percentage changes of Sr, Hf, and O in pure and Sr included composites thin films. The XPS spectrum has confirmed Sr in SrO2 and Sr2HfO4 phases, and its oxidation states in different phases were verified using short XPS scans. The I–V curves of pure (Al/HfO2/n-Si) and Sr:HfO2 composite (Al/Sr–HfO2/n-Si) diodes were studied and compared. The 15% Sr included HfO2 showed higher rectification behavior when compared with pure Al/HfO2/n-Si and composited (5 and 10%) Al/Sr–HfO2/n-Si at room temperature. [ABSTRACT FROM AUTHOR]

Strontium cobalt oxide (SrCoO3-δ) nanoparticles were successfully synthesized using; composite mediated hydrothermal (CMHM), without water and surfactants (WOWS) sol-gel and co-precipitation methods. The probable electrical conduction mechanism of synthesized strontium cobaltite was investigated via complex impedance analysis. Characterization techniques were employed to study the dependence of structure, homogeneity, physical parameters and electrical properties on synthesis procedures. After heat treatment, X-Ray Diffraction (XRD) confirmed the formation of phase pure SrCoO3-δ powders synthesized with CMHM, WOWS sol-gel and co-precipitation methods. Fourier Transform Infrared Spectroscopy (FTIR) spectra indicated the presence of fingerprint region of perovskite (ABO3-δ) structure. Raman spectroscopy revealed the internal motion of oxygen inside the CoO6 octahedra of SrCoO3-δ perovskite structure. A Raman phonon mode under 600 cm−1 position was identified which is commonly observed for such perovskite oxide. Scanning Electron Microscopy (SEM) images showed uniformly diffused, microporous and agglomerated sphere like morphology. Differential Thermal Analysis (DTA) and Thermogravimetry (TGA) verified formation of intermediate metal carbonates that decomposed to final product. Complex impedance spectroscopic plots (Nyquist plots) against frequency (20 Hz–3 MHz) discovered single semi-circular arcs in the low frequency region. These arcs showed that, grain boundary contribution is dominated over grain contribution to the total electrical conduction behavior. Modulus analysis disclosed non-Debye type conductivity relaxation in hydrothermally synthesized samples. The AC conductivity graphs followed Jonscher's power law and hopping model. Hydrothermally synthesized samples exhibited minimum impedances and maximum AC conductivity, which makes them excellent candidate for cathode material in intermediate temperature range solid oxide fuel cells (IT-SOFCs) applications. [ABSTRACT FROM AUTHOR]