Search results for "engineering.material"
showing 10 items of 2352 documents
Vapor-Deposited Perovskites: The Route to High-Performance Solar Cell Production?
2017
Summary High-quality semiconducting perovskites can be easily synthesized through several methods. The ease of fabrication has favored the adoption of lab-scale solution-processing techniques, which have yielded the highest performing devices. Most of these processes, however, are not directly applicable to larger scale and volume preparations, hindering the consolidation and market entry of this technology. Vapor-based methods, a mature technology widely adopted in the coating and semiconductor industry, could change this trend. Their application to perovskite solar cells includes a large amount of fabrication approaches, offering versatility in the employed materials as well as in the cha…
Novel procedure for the template synthesis of metal nanostructures
2008
In this work we describe a novel method for the fabrication of a regular and uniform array of Cu nanowires into anodic alumina membranes. It is based on galvanic contact between the metal sputtered film covering the bottom of template and a less noble metal. The growth rate was estimated as function of the immersion time. Nanowires with aspect ratio from 12 to 286 were obtained by adjusting the deposition time. Copper nanowires were found to be polycrystalline with an average crystalline size of about 40 nm. This procedure can be applied for the preparation of a wide range of metallic nanostructures and it can be easily scaled up for industrial processing. Keywords: Displacement deposition,…
High-resolution transmission electron microscopic investigations of molybdenum thin films on faceted α-Al2O3
2005
Epitaxially grown Mo films on a faceted corundum (α-Al2O3)mplane were investigated by transmission electron microscopy. Low- and high-resolution images were taken from a cross-section specimen cut perpendicular to the facets. It was possible to identify unambiguously the crystallographic orientation of these facets and explain the considerable deviation (∼10°) of the experimental interfacet angle, as measured with atomic force microscopy (AFM), from the expected value. For the first time, proof is given for a smooth \{10\bar{1}1\} facet and a curvy facet with orientation near to \{10\bar{1}\bar{2}\}. Moreover, the three-dimensional epitaxial relationship of an Mo film on a faceted corundumm…
Evolution of the middle Paleozoic magmatism in the Chinese Altai: Constraints on the crustal differentiation at shallow depth in the accretionary oro…
2019
Abstract The Chinese Altai underwent intensive mafic and felsic magmatism in the middle Paleozoic, which was the most important magmatic event in the region. It is still unclear for the role of the event in formation of the crust that is thick (∼56 km) and has structure of three-layer stratification. In this study, the data for the middle Paleozoic mafic rocks and granites are comprehensively compiled and integrated with new geochronological, petrological, geochemical and Sr-Nd-Pb isotopic data for gabbroic rocks from Keketuohai area and tonalite and biotite granites from Habahe area. The middle Paleozoic mafic rocks exhibit two evolutionary trends, which can be defined as high-Al and low-A…
Age and evolution of late Mesozoic metamorphic core complexes in southern Siberia and northern Mongolia
2008
Numerous Cretaceous metamorphic core complexes (MCCs) extend from Transbaikalia in Russia to northern Mongolia within the Central Asian Orogenic Belt. We investigated the Buteel and Zagan MCCs in detail. Shear sense indicators in mylonitized rocks show footwall-to-the-NW tectonic transport. Single zircon dating of footwall rocks in the Buteel MCC establishes the emplacement of granitoid orthogneiss precursors at 240–211 Ma, a felsic metavolcanic rock at 265.0 ± 1.2 Ma, a syenite at 265.5 ± 1.2 Ma and a metarhyolite of the pre-granitoid basement at 553.6 ± 2.9 Ma. A peralkaline granite intruding orthogneisses of the Zagan MCC has a new U–Pb zircon age of 151.6 ± 0.7 Ma. 40Ar/39Ar ages of 133…
Field and petrographic evidence for partial melting of TTG gneisses from the central region of the mainland Lewisian complex, NW Scotland
2013
The central region of the mainland Lewisian complex is dominated by granulite-facies tonalite–trondhjemite–granodiorite (TTG) gneisses that are highly depleted in some mobile trace elements (Cs, Rb, Th and U) relative to amphibolite-facies TTG gneisses elsewhere in the Lewisian complex and to the average composition of TTG gneisses worldwide. Over almost half a century of research there has been vigorous debate as to the origin of this depletion, in particular with respect to the role of partial melting and melt loss. Here we provide field and petrographic evidence that TTG gneisses across the central region partially melted during granulite-facies (Badcallian) metamorphism. Partial melting…
Interstitial defects in diamond: A quantum mechanical simulation of their EPR constants and vibrational spectra
2020
The local geometry, electronic structure, and vibrational features of three vicinal double interstitial defects in diamond, ICIC, ICIN, and ININ, are investigated and compared with those of three "simple" ⟨100⟩ interstitial defects, ICC, ICN, and INN, previously reported by Salustro et al. [Phys. Chem. Chem. Phys. 20, 16615 (2018)], using a similar quantum mechanical approach based on the B3LYP functional constructed from Gaussian-type basis sets, within a supercell scheme, as implemented in the CRYSTAL code. For the first time, the Fermi contact term and hyperfine coupling tensor B of the four open shell structures, ICIC, ICIN, ICC, and ICN, are evaluated and compared with the available ex…
Mass transfer in nonisothermal ferrocolloids under the effect of a magnetic field
1999
Abstract The paper presents a review of newest experimental results on particle thermal diffusion in hydrocarbon based ferrofluids. The measurements are performed using a vertical thermal diffusion column, the Soret coefficient is evaluated from particle separation curves employing a simple column theory which accounts for thermal convection in the vertical channel forced by a concentration buoyancy force arising during the thermophoretic transfer of heavy particles. High positive values of the Soret coefficient of lyophilized Fe 3 O 4 and Mn x Zn 1− x Fe 2 O 4 particles in surfacted tetradecane based colloids are measured. Experiments confirm the theoretically predicted anisotropy of parti…
Magnetically enhancing the Seebeck coefficient in ferrofluids.
2019
The influence of the magnetic field on the Seebeck coefficient (Se) was investigated in dilute magnetic nanofluids (ferrofluids) composed of maghemite magnetic nanoparticles dispersed in dimethyl-sulfoxide (DMSO). A 25% increase in the Se value was found when the external magnetic field was applied perpendicularly to the temperature gradient, reminiscent of an increase in the Soret coefficient (ST, concentration gradient) observed in the same fluids. In-depth analysis of experimental data, however, revealed that different mechanisms are responsible for the observed magneto-thermoelectric and -thermodiffusive phenomena. Possible physical and physico-chemical origins leading to the enhancemen…
Assisted phytostabilization of soil from a former military area with mineral amendments.
2019
Abstract Due to the presence of toxic pollutants, soils in former military areas need remedial actions with environmentally friendly methods. Greenhouse experiments were conducted to investigate the aided phytostabilization of multi-heavy metals (HMs), i.e. Cd, Cr, Cu, Ni, Pb, Zn, in post-military soil by Festuca rubra and three mineral amendments (diatomite, dolomite and halloysite). The amendments were applied at 0 and 3.0% to each pot filled with 5 kg of polluted soil. After seven weeks of the phytostabilization, selected soil properties, biomass yield of F. rubra and immobilization of HMs by their accumulation in plant and redistribution among individual fractions in soil were determine…