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Abstract: The use of aerosol assisted chemical vapour deposition (AACVD) for the formation of zinc oxide and doped ZnO films with control of preferred orientation on glass is reported. Undoped and doped ZnO host matrix films were highly transparent with visible transmission >85%. The Cu (CuO/Cu2O) doped ZnO thin films were highly coloured and opaque. Undoped and noble metal doped ZnO films had mainly spherical morphology. Aluminium oxide/ZnO composite films had a range of morphologies from spherical to cubic. The XRD patterns for both doped and undoped ZnO films grown at substrate temperatures less than 500°C showed strong preferred (002) crystal lattice orientation. The undoped ZnO film at 500°C exhibited a random crystal orientation pattern for hexagonal ZnO. The introduction of small amounts of Al2O3 within the ZnO to form a composite significantly altered the preferred crystal orientation to (101). [Copyright &y& Elsevier]

Studies the synthesis of binary chalcogenide and pnictide materials by metathetical reactions in liquid ammonia. Isolation of crystalline nanoscaled materials; X-ray diffraction analysis of the preannealed materials; Annealing of X-ray amorphous chalcogenides; Band gap measurements of the metal chalcogenides by optical measurements; Laser induced fluorescence spectra of cadmium sulfide.

Describes the characterization of dinuclear metallic complexes of molybdenum and tungsten derived from 2,5-dimethylhexane-2,5-diol. Role of chelating ligands in mononuclear systems; Kinetic products of the reactions of the dimetallic compounds in hydrocarbon solvents; Kinetic barriers affecting the formation of the dimetallic complexes.

A control thick-film SnO 2 gas sensor was modified with zeolites holding LTA, FAU and MFI frameworks using two different approaches to integrate them into the gas-sensing interface. The objective was to prompt selectivity and sensitivity enhancements that were otherwise unattained with the unmodified material when detecting a range of hydrocarbon vapours with similar molecular structures and kinetic diameters. Molecules with different functional groups were also explored. Overlayers were designed by screen-printing 1 or 3 zeolite depositions on top of the control sensor. Admixtures were prepared by screen-printing composites of the control material with 10% (w/w) and 30% (w/w) of zeolite. Tests were performed against ethane, propane, butane, ethanol, isopropanol, acetone, toluene and carbon monoxide at concentrations in the 2.5–125 ppm range and sensors were heated to temperatures in the 250–500 °C range. Sensors were also exposed to humid air and to a mixture of ethane and humid air to assess the selective capabilities of the sensing materials in mixed-gas environments. Both fabrication methods provided sensor responses that, combined, favoured vapour discrimination in a way unachievable with the control sensor and the presence of zeolite was seen to assist in sensitivity and selectivity enhancements towards vapours, whilst providing stable and repeatable responses over time. [ABSTRACT FROM AUTHOR]

• Correct SPME fibre placement is key to determining the background from object. • Temperature fluctuations have a dramatic effect on the resulting VOC profile. • Exposure of the fibre for 1-day resulted in the best repeatability. • Exposure for 7-days was the most vulnerable to external influences. • Despite the difficulties, SPME provided insight into the condition of the object. Currently there is no proven method for in-situ monitoring of the decay progression of objects featuring polymeric materials. One potential method which is gaining traction, is the analysis of volatile organic compounds (VOC) via solid phase microextraction gas chromatography mass spectrometry (SPME-GC/MS). Few studies have focused on repeated, long-term monitoring of objects in open heritage environments via SPME-GC/MS. Specifically, the combined effects on methodological performance of the fibre exposure time in conjunction with the effects of variable environmental conditions over that period and fibre location with relation to the object have yet to be investigated. In order to study these effects, we tracked four key VOCs emitted from Naum Gabo's constructivist sculpture Construction in Space 'Two Cones' (Tate) by repeated SPME-GC/MS analysis. Five fibres in total were placed around the object and within its storage room. Two separate experimental campaigns were carried out, one exposing the fibres to the object for 1 Day, the other for 7 days. Our results show that an exposure time of 7 Days led to a lower relative standard deviation than for a 1 Day exposure time for each of the four VOCs. However, our results also show that the performance of individual fibres, at their specific locations, was better with an exposure time of 1 Day. Furthermore, we highlight the comparability of the background VOC profile to a location within the object's storage crate. The implications of our research are two-fold – firstly, when monitoring in an open environment, a shorter exposure time leads to more repeatable analysis over long time periods, however, it is at the expense of the ability to calculate concentrations as the fibre has not yet reached equilibrium. Secondly, background and object VOC profiles can be difficult to distinguish unless the fibre is in immediate vicinity of the point of interest. [ABSTRACT FROM AUTHOR]

Tantalum phosphide coatings were prepared by chemical vapour deposition reaction of TaCl5 and PH2Cy at 350–500 °C. The films are hard, stable to corrosive environments and show reflection properties in the infrared. [Copyright &y& Elsevier]

Abstract Cubic, terraced, and spherical Mg-MgO nanoparticles (NPs), ranging in average particle size from 30 up to 80 nm, were prepared through vaporization and condensation of Mg metal in mix gas flow (argon + air) at conditions of the levitation-jet aerosol synthesis. These NPs were collected in three zones, located at different distances from an evaporator. Scanning electron microscopy (SEM), X-ray diffraction (XRD), BET measurements, UV–Vis, FT-IR, Raman, XPS, and vibrating-sample magnetometry (VSM) were used for characterized of NPs. The results indicated an essential effect of synthesis conditions on the nanoparticle properties. Room temperature ferromagnetism with the maximum magnetization of up to 0.65 emu/g was found in the nanoparticles. The maximum specific magnetization of the NPs depends on the value of specific surface area multiplied by oxide content in the form of two-peaks function. It was discovered a clear increase in the maximum magnetization of NPs, collected in the different zones, with an increase in the distance of these zones from the evaporator. It was suggested that the observed ferromagnetic ordering may be related to the Mg-deficient defects on the surface of NPs. This suggestion was in agreement with the results of optical experiments, particularly, with an increase in the Raman peak intensities. In addition, XPS studies reveal an oscillating quenching dependence of the maximum magnetization on Mg 2p peak width value. It was also supposed that various values of the maximum magnetization origin from the different fabrication conditions promoting defects propagation on the surface of NPs. Graphical abstract Image 1 Highlights • Levitation-jet synthesis of Mg O nanoparticles (NPs) at different conditions. • Cubic, terraced, and spherical NPs in average particle sizes from 30 up to 80 nm. • RT ferromagnetism (RTFM) in the NPs with maximum magnetization up to 0.65 emu/g. • Dependence of the magnetization on specific surface area multiplied by MgO content. • Oscillating quenching dependence of the maximum magnetization on Mg 2p peak width. [ABSTRACT FROM AUTHOR]

As a very promising thermochromic material, VO 2 (M/R) (Monoclinic/Rutile) has not been widely applied in smart windows due to its intrinsic low solar modulation (ΔT sol ) and low luminous transmission (T lum ). To address this issue, porous structures have been introduced into the VO 2 film. Herein, mesoporous VO 2 powders with pore size of about 2–10 nm were synthesized using cotton as template by hydrothermal methods. The pore and crystal size of the synthesized VO 2 powders can be reliably controlled by the hydrothermal temperature. The mesoporous VO 2 powders were mixed with PVP to prepare the VO 2 -based nanocomposite films by spin coating. The VO 2 -based films show a better performance between ΔT sol and T lum than that appeared in previous reports. Especially, a larger pore size could lead to a higher visible transmittance and a larger crystal size would facilitate the enhancement in the solar modulation. In this sense, the VO 2 -based film obtained at the hydrothermal temperature of 180 °C exhibits an outstanding thermochromic performance with ΔT sol of 12.9% and T lum up to 56.0% due to a larger crystal size and pore size. Therefore, this synthetic route shows a potential method for the application of mesoporous VO 2 powders for solar control coatings. [ABSTRACT FROM AUTHOR]

Octahedral and roughly spherical In-In 2 O 3 nanoparticles ranging in average particle size from 30 up to 300 nm were prepared by levitation-jet aerosol synthesis through condensation of metal indium vapor in helium gas flow with gaseous oxygen/air injection at ambient and reduced pressure. Scanning electron microscopy (SEM), X-ray diffraction (XRD), BET measurements, UV–vis, FT-IR, Raman, XPS, and vibrating-sample magnetometry (VSM) characterized the nanoparticles. Room-temperature ferromagnetism with maximum magnetization of up to 0.17 emu/g was recorded for the nanoparticles. The results indicate a predominant role of the actual microstructure on the nanoparticle properties. It is suggested that the observed ferromagnetic ordering may be related to intrinsic defects at the In/In 2 O 3 interface structure of such a composite material. This suggestion is in good agreement with the results of optical and XPS experiments on the NPs. [ABSTRACT FROM AUTHOR]

Studies the magnetic structures of the triangular lattice magnets AFe(SO4)2 (A=K, Rb, Cs). How the magnetic Fe3+ ions form in these magnets; Illustration of the relationship between the regular triangular lattice and the row; Examination of the low temperature magnetic structures adopted by title compounds; Results of this study.

This work describes the first Aerosol Assisted Chemical Vapour Deposition (AACVD) synthesis of photocatalytic titanium dioxide thin films embedded with synthetic hydroxyapatite, [Ca 10 (PO 4 )(OH) 2 ], nanoparticles. The hydroxyapatite nanoparticles were prepared using a low temperature continuous hydrothermal flow synthesis method; analysis of the hydroxyapatite powder showed that it was phase pure and that the as-prepared material was made up of nano-needles. The nanoparticles were then embedded into TiO 2 coatings using the AACVD technique by suspending them in a solution of the titania precursor (titanium tetra-isopropoxide). Results showed that the hydroxyapatite, although present in very low concentrations in the coatings (not detectable by XRD or Raman spectroscopy), heavily affected their morphology, depending on their concentration in the precursor solution. Tests of the photocatalytic activity of the composite films showed that the inclusion of the hydroxyapatite led to an increase in methylene blue photodegradation (up to 50% higher) and that the materials were photostable. This study shows that TiO 2 coatings embedded with hydroxyapatite nanoparticles have potential as highly efficient photocatalysts. [ABSTRACT FROM AUTHOR]

Aqueous dispersions of tin-doped indium oxide (ITO) nanopowder were prepared and the effect of the addition of PEG 400, Tween 80 and β-alanine as dispersants was investigated using zeta potential and particle size distribution measurements. Both PEG 400 and β-alanine were found to produce stable dispersions that were used to deposit ITO thin films on glass substrates by dip and spin coating methods. The ITO thin films were heat-treated using both conventional and microwave heat treatment in order to improve the inter-particle connections and hence the resistivity and transparency of the films. All the films exhibited an average transmittance of >80% over the visible spectrum after being subjected to the heat treatment process. ITO films prepared with no dispersant showed very high resistivity values for both heating methods, however addition of 2 wt% PEG 400 to the dispersion yielded a reduction in the resistivity values to 1.4×10 −1 Ω cm and 3.8×10 −2 Ω cm for conventionally and microwave treated films, respectively. The surface morphological studies confirmed that addition of dispersants improved the film uniformity and inter-particle connections of the ITO films considerably. [ABSTRACT FROM AUTHOR]

Cubic and near-spherical TiN nanoparticles ranging in average size from 20 to 125 nm were prepared by levitation-jet aerosol synthesis through condensation of titanium vapor in an inert gas flow with gaseous nitrogen injection. The nanoparticles were characterized by using scanning electron microscopy (SEM), X-ray diffraction (XRD), BET measurements, UV–Vis, FT-IR, Raman spectroscopy, XPS, and vibrating-sample magnetometry. Room-temperature ferromagnetism with maximum magnetization up to 2.5 emu/g was recorded for the nanoparticles. The results indicate that the observed ferromagnetic ordering was related to the defect Ti–N structures on the surface of nanoparticles. This suggestion is in good correlation with the measured spectroscopical data. [ABSTRACT FROM AUTHOR]

Abstract: Metallic oxide coatings, for example TiO2, are of increasing technological importance in a wide range of industrially relevant functional surfaces on components for renewable energy sector, self-cleaning, antimicrobial surfaces etc. Reactive closed field unbalanced magnetron sputter ion plating (CFUBMSIP) provides an effective, industrially-compatible processing route for the deposition of metallic oxides, with controlled composition, structure, mechanical, electronic and optical properties. The production of crystallized as-deposited TiO2 thin coatings by reactive CFUBMSIP process is described. The arrangement of the deposition system; deposition parameters, including: working gases, deposition pressure, the sputtering power; and the influence of interlayer on the nucleation and the crystalline structure of TiO2 coatings are investigated. [Copyright &y& Elsevier]

Highlights: [•] Structural and magnetic characterization of aerosol Ni nanoparticles. [•] Experimental parameters affecting size, shape and composition are discussed. [•] Larger spherical particles with the highest Ni content are produced by using an Ar flow. [•] Coalescence rate of primary particles is accelerated by increasing Ni feeding rate. [•] Ni nanoparticles show bulk-like saturation magnetization values. [ABSTRACT FROM AUTHOR]

Highlights: [•] Structural and magnetic characterization of cubic-shaped aerosol NiO nanoparticles. [•] Procedure for subtracting an underlying diamagnetic contribution. [•] Correlation between specific surface area of NPs and their diamagnetic susceptibility. [•] Critical transition temperature associated to a hypothetical superconductive state. [Copyright &y& Elsevier]

Abstract: A simple model of the microstructure of a sensor as a network of three resistors, representing the surface, the bulk and the particle boundary, is combined with a simple model of sensor response in order to understand the effects of sintering temperature on response of a ceramic gas-sensitive resistor. This description accurately fitted the response of chromium titanium oxide to carbon monoxide over a range of four orders of magnitude in gas concentration. The parameters representing the microstructure are found to vary with sintering temperature according to predictions made from microscopy of the structures. The parameter representing chemistry also varied with sintering temperature: understandable because titanium segregation, which is the major determinant of the charge carrier distribution, varies with sintering temperature. [Copyright &y& Elsevier]

Abstract: Porous anodized alumina (PAA) and macroporous silicon (MS) substrates have been used to template the growth of tungsten oxide via aerosol assisted chemical vapour deposition from the precursor tungsten hexaphenoxide. The results show that thin PAA substrates have potential as templates for growing microstructured tungsten oxide films and MS substrates cause the growth of ‘grids’ of polycrystalline tungsten oxide. [Copyright &y& Elsevier]