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Direct laser interference patterning (DLIP) is a versatile technique for surface patterning that enables formation of micro-nano sized periodic structures on top of the target material. In this study, DLIP in high pressure, supercritical and liquid CO2 by 4-beam DLIP was used to pattern titanium and zinc targets. Field emission scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy was used to characterize the patterned surfaces. Field emission SEM analysis showed presence of ordered uniform donut ring pattern with hollow centers for both titanium and zinc with a period slightly under 3 µm while topographical images from atomic force microscopy revealed donut rings protruding outwards typically around 200 nm from target surface and consisted of a crevice at the center with a depth typically around 300 nm and 250 nm for titanium and zinc target, respectively. Based on X-ray photoelectron spectroscopic analysis, this is the first study to report formation of TiO2, TiC, ZnCO3, and zinc hydroxy carbonate on the pattern by DLIP in supercritical and liquid CO2 for titanium and zinc targets. Pressurized CO2 is demonstrated as a promising environment with mirror-based DLIP system for reactive patterning. Due to the superior transport properties and solvent power of supercritical CO2, the current study opens possibilities for reactive patterning in environments that may not have been previously possible. [ABSTRACT FROM AUTHOR]

Direct laser interference patterning (DLIP) is a versatile technique for surface patterning that enables formation of micro-nano sized periodic structures on top of the target material. In this study, DLIP in high pressure, supercritical and liquid CO2 by 4-beam DLIP was used to pattern titanium and zinc targets. Field emission scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy was used to characterize the patterned surfaces. Field emission SEM analysis showed presence of ordered uniform donut ring pattern with hollow centers for both titanium and zinc with a period slightly under 3 µm while topographical images from atomic force microscopy revealed donut rings protruding outwards typically around 200 nm from target surface and consisted of a crevice at the center with a depth typically around 300 nm and 250 nm for titanium and zinc target, respectively. Based on X-ray photoelectron spectroscopic analysis, this is the first study to report formation of TiO2, TiC, ZnCO3, and zinc hydroxy carbonate on the pattern by DLIP in supercritical and liquid CO2 for titanium and zinc targets. Pressurized CO2 is demonstrated as a promising environment with mirror-based DLIP system for reactive patterning. Due to the superior transport properties and solvent power of supercritical CO2, the current study opens possibilities for reactive patterning in environments that may not have been previously possible. [ABSTRACT FROM AUTHOR]

The rise of low-temperature atomic layer deposition (ALD) has made it very attractive to produce high- κ dielectric for flexible electronic devices. Similarly, selective deposition of ALD films is of great relevance for circuitry. We demonstrated a simple method of using a physical mask to block the film's growth in selected polymeric and flexible substrate areas during a low-pressure ALD process. A low-cost silicone adhesive polyimide tape was used to manually mask selected areas of bare substrates and aluminum strips deposited by evaporation. 190 cycles of aluminum oxide (Al 2 O 3) and hafnium oxide (HfO 2) were deposited at temperatures ranging from 100 to 250 ° C. Using x-ray photoelectron spectroscopy (XPS) analysis and energy dispersive x-ray spectroscopy (EDS), we showed that the mask was effective in protecting the areas under the tape. The mask did not show any modification of shape for an exposure of 10 h at 250 ° C, hence keeping the form of the masked area intact. An analysis of the unmasked area by ellipsometry (632.8 nm) and x ray shows a regular film with a thickness variation under 2 nm for a given temperature and constant refractive index. EDS, selected-area XPS, and imaging XPS show an evident change of elemental content at the interface of two areas. By XPS, we established that the structure of the films was not affected by the mask, the films were stoichiometric, and there was no effect of outgassing from the adhesive film. [ABSTRACT FROM AUTHOR]

Novel monoisomeric perylene imide derivatives with terpyridinyl and pyrrolidinyl substituents were synthesized and deposited onto solid substrates, such as a thin film of Al2O3 and mesoporous TiO2 nanoparticle layer, by using a simple dip-bydip method. Arrays of up to 33 layers were built on Al2O3. In the case of mesoporous TiO2, the interstitial volume between the particles was filled up with dye assemblies. Deposition could produce either layers of microcrystals or molecular layers if an appropriate washing procedure was used. The resultant arrays were studied by means of scanning electron microscopy, X-ray photoelectron spectroscopy measurements, and UV/Vis absorption. [ABSTRACT FROM AUTHOR]

In this work, polycrystalline Cu(Ag) bulk alloy (1 wt.% Ag) and Ag/Cu(100) surface alloy (0.9 ML Ag) have been characterized by x-ray photoelectron spectroscopy (XPS) employing Al Kα and Mg Kα radiation. XPS spectra of the principal core levels (Cu, Ag) are presented together with XAES (x-ray induced Auger electron spectroscopy) spectra of the Cu LMM transition. The samples were prepared in situ by argon ion sputtering at room temperature and subsequent annealing at 700 K. Ag overlayer was deposited on the Cu(100) surface by a resistively heated Ag evaporator. The absence of contaminants such as C or O was confirmed by XPS. Together, the industrial Cu(Ag) alloy and the well defined Ag/Cu(100) model system serve as a template for studies of nanoscale surface oxidation and segregation phenomena. [ABSTRACT FROM AUTHOR]

Direct laser interference patterning (DLIP) is a versatile technique for surface patterning that enables formation of micro-nano sized periodic structures on top of the target material. In this study, DLIP in high pressure, supercritical and liquid CO2 by 4-beam DLIP was used to pattern titanium and zinc targets. Field emission scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy was used to characterize the patterned surfaces. Field emission SEM analysis showed presence of ordered uniform donut ring pattern with hollow centers for both titanium and zinc with a period slightly under 3 µm while topographical images from atomic force microscopy revealed donut rings protruding outwards typically around 200 nm from target surface and consisted of a crevice at the center with a depth typically around 300 nm and 250 nm for titanium and zinc target, respectively. Based on X-ray photoelectron spectroscopic analysis, this is the first study to report formation of TiO2, TiC, ZnCO3, and zinc hydroxy carbonate on the pattern by DLIP in supercritical and liquid CO2 for titanium and zinc targets. Pressurized CO2 is demonstrated as a promising environment with mirror-based DLIP system for reactive patterning. Due to the superior transport properties and solvent power of supercritical CO2, the current study opens possibilities for reactive patterning in environments that may not have been previously possible. [ABSTRACT FROM AUTHOR]

Direct laser interference patterning (DLIP) is a versatile technique for surface patterning that enables formation of micro-nano sized periodic structures on top of the target material. In this study, DLIP in high pressure, supercritical and liquid CO2 by 4-beam DLIP was used to pattern titanium and zinc targets. Field emission scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy was used to characterize the patterned surfaces. Field emission SEM analysis showed presence of ordered uniform donut ring pattern with hollow centers for both titanium and zinc with a period slightly under 3 µm while topographical images from atomic force microscopy revealed donut rings protruding outwards typically around 200 nm from target surface and consisted of a crevice at the center with a depth typically around 300 nm and 250 nm for titanium and zinc target, respectively. Based on X-ray photoelectron spectroscopic analysis, this is the first study to report formation of TiO2, TiC, ZnCO3, and zinc hydroxy carbonate on the pattern by DLIP in supercritical and liquid CO2 for titanium and zinc targets. Pressurized CO2 is demonstrated as a promising environment with mirror-based DLIP system for reactive patterning. Due to the superior transport properties and solvent power of supercritical CO2, the current study opens possibilities for reactive patterning in environments that may not have been previously possible. [ABSTRACT FROM AUTHOR]

A versatile and economic method of preparing covalently-bound and uniform bifunctional silane monolayers on stainless steel is presented. Stainless steel is first electrochemically hydroxylated to enable the formation of a bifunctional overlayer via simultaneous liquid-phase deposition of two organofunctional silanes: (3-aminopropyl)trimethoxysilane (APS) and (3-mercaptopropyl)trimethoxysilane (MPS). The chemical composition, in-depth distribution, molecular orientation and chemical bonds in APS, MPS and APS/MPS layers over a range of APS/MPS mixing ratios are studied with synchrotron radiation mediated photoelectron spectroscopy (SR-PES), conventional X-ray photoelectron spectroscopy (XPS) and energy filtered X-ray photoemission electron microscopy (EF-XPEEM). Inelastic electron energy-loss background (IEEB) analysis is employed to determine the surface morphology of the silanized samples. Coadsorption is shown to produce a covalently-bound and highly ordered monolayer with a controllable MPS surface concentration within APS matrix. The results show evidence of strong synergistic effects during simultaneous adsorption of MPS and APS from liquid phase. While the uptake of MPS alone is low, the coadsorption of MPS and APS strongly enhances both the uptake of MPS and ordering in the APS/MPS overlayer. Results from PES, EF-XPEEM and IEEB analysis reveal that the surface is predominantly covered by a well-ordered APS/MPS monolayer with only slight degree of clustering. Clustering is attributed to different hydrolysis rates in solution and structural irregularities on the substrate. Our results conclusively invalidate the assumption that APS/MPS ratio in a deposited overlayer should correlate linearly with the mixing ratio in solution. The reported insights into the chemical bonds, molecular orientation and morphology in APS/MPS overlayers facilitate site-selective coupling of functional molecules to amino and thiol groups with controllable spatial distribution and, in general, knowledge-based development of novel surface functionalities for stainless steel and other metal (alloy) oxides. [ABSTRACT FROM AUTHOR]

[Display omitted] • Introducing S + P simultaneously on catalyst is essential in deactivation studies. • Formed AlPO 4 blocked adsorption sites for sulfur to form Al 2 (SO 4) 3. • Sulfur species remain with Pt particles leading more severe poisoning of catalyst. Simultaneous poisoning of sulfur + phosphorus on a platinum-based diesel oxidation catalyst was studied to gain a deeper understanding on the catalyst deactivation. Compared to a single poisoning (sulfur or phosphorus), the simultaneous poisoning had a severe effect on the catalyst activation: light-off temperature for 90% conversion of propene was not reached, this of carbon monoxide was much higher than expected, and the maximum conversion of nitrogen monoxide collapsed. With very comprehensive structural characterization by various methods (e.g. STEM-EDS, XPS, DRIFTS) used, we achieved to conclude an explanation for this. In the case of the S + P-poisoning of the catalyst, formed aluminum phosphate was found to block adsorption sites for sulfur species on alumina and sulfur adsorbs mainly on cerium oxides. In addition, sulfur species remain with and in the vicinity of the platinum particles blocking active sites. [ABSTRACT FROM AUTHOR]

We report on the properties of magnesium fluoride (MgF 2) thin films deposited by electron beam evaporation as a function of substrate deposition temperature and ex-situ annealing temperature. In particular, we report on the dependence of refractive index on annealing temperature, which can be used as a tuning parameter of the optical properties. Mechanical and structural properties of the films influenced by the annealing are also examined. Changing the substrate temperature from 50 °C to 240 °C caused a decrease of the refractive index and the lowest value of 1.36 (measured at 632.8 nm) was achieved for the substrate temperature of 240 °C. Rapid thermal annealing further decreased the refractive indices to slightly below 1.32. This could indicate increase in the film porousness and removal of adsorbed water molecules. Prior annealing the film surfaces were very smooth with root mean square and mean roughness below 1 nm. Annealing above 700 °C changed the structure of the films drastically, as they started to form a granular structure, while an annealing temperature of 1000 °C increased the refractive index to a value as high as 1.5. Using X-ray photoelectron spectroscopy we show that the surface of the films consist mainly of Mg and F atoms, but also small traces of C and O are present. The Mg:F ratio remained essentially the same (43:57) between different deposition temperatures. To demonstrate the need for post-deposition annealing treatment, we have also studied the aging effect in the MgF 2 based anti-reflective coatings. Image 1 • Assessment of the as-deposited and post-deposition properties of MgF 2 thin films with ellipsometry, XPS, SEM, and AFM. • Effective display of the aging behavior of MgF 2 thin films and change of properties due time. • Characterization of the influence of post-deposition RTA to film properties, such as porosity and refractive index. • Connection of the material and aging properties to applications, like broadband anti-reflective coatings for solar cells. [ABSTRACT FROM AUTHOR]