Search results for "Materials"
showing 10 items of 29608 documents
Stealth dicing with Bessel beams and beyond
2016
In the context of laser cutting of transparent materials, we investigate glass cleaving with Bessel beams and report that a modification of the beam with 3 main lobes drastically enhances cleavability and reduces defects.
Effect of Fe-incorporation on Structural and Optoelectronic Properties of Spin Coated p/n Type ZnO Thin Films
2020
Formulas for the thermodynamic properties of dense nitrogen.
1969
Phonons in MoSe2/WSe2 van der Waals heterobilayer
2021
We report first-principles calculations of the structural and vibrational properties of the synthesized two-dimensional van der Waals heterostructures formed by single-layers dichalcogenides MoSe2 and WSe2. We show that, when combining these systems in a periodic two-dimensional heterostructures, the intrinsic phonon characteristics of the free-standing constituents are to a large extent preserved but, furthermore, exhibit shear and breathing phonon modes that are not present in the individual building blocks. These peculiar modes depend strongly on the weak vdW forces and has a great contibution to the thermal properties of the layered materials. Besides these features, the departure of fl…
Synchrotron x-ray transmission measurements and modeling of filters investigated for Athena
2020
International audience; Advanced Telescope for High-Energy Astrophysics is a large-class astrophysics space mission selected by the European Space Agency to study the theme "Hot and Energetic Universe." The mission essentially consists of a large effective area x-ray telescope and two detectors: the X-ray Integral Field Unit (X-IFU) and the Wide Field Imager (WFI). Both instruments require filters to shield from out-of-band radiation while providing high transparency to x-rays. The mission is presently in phase B; thus, to consolidate the preliminary design, investigated filter materials need to be properly characterized by experimental test campaigns. We report results from high-resolution…
Towards Controlled Synthesis of Water-Soluble Gold Nanoclusters : Synthesis and Analysis
2019
Water-soluble gold nanoclusters with well-defined molecular structures and stability possess particular biophysical properties making them excellent candidates for biological applications as well as for fundamental spectroscopic studies. The currently existing synthetic protocols for atomically monodisperse thiolate-protected gold nanoclusters (AuMPCs) have been widely expanded with organothiolates, yet the direct synthesis reports for water-soluble AuMPCs are still deficient. Here, we demonstrate a wet-chemistry pH-controlled synthesis of two large water-soluble nanoclusters utilizing p-mercaptobenzoic acid (pMBA), affording different sizes of plasmonic AuMPCs on the preparative scale (∼7 …
An Easy Route Towards Regioselectively Difunctionalized Cyclens and New Cryptands.
2006
Reductive amination of various aldehydes with cyclen represents a very convenient method for the synthesis of a wide range of 1,7-difunctionalized cyclens, as well as new cryptands.
Dyes of a Shadow Theatre: Investigating Tholu Bommalu Indian Puppets through a Highly Sensitive Multi-Spectroscopic Approach
2021
Tholu Bommalu are typical leather puppets of the traditional Indian shadow theatre. Two of these objects are part of a collection in the International Puppets Museum “Antonio Pasqualino” (Palermo, Sicily, Italy), which can count on one hundred-seventy-three of artifacts. These Indian puppets were investigated to obtain information related to the use of dyes for their manufacturing through a multi-technical approach exploiting the combination of highly sensitive spectroscopic techniques. Wet cotton stubbons were used to entrap small particles of dyes on the fibers from the art objects for the consequent analyses. Visible Light Micro-Reflectance spectroscopy was employed for the preliminary i…
Heavy-Ion-Induced Defects in Degraded SiC Power MOSFETs
2023
Cathodoluminescence spectroscopy is used to investigate the formation of point- and extended defects in SiC power MOSFETs exposed to heavy-ions. Devices showing single event leakage current (SELC) effects are analysed and compared to pristine samples. Common luminescence peaks of defect centers localized in the thermal-SiO2 are identified, together with peaks at the characteristic wavelength of extended defects.
High speed microfluidic prototyping by programmable proximity aperture MeV ion beam lithography
2013
Abstract Microfluidics refers to the science and technology for controlling and manipulating fluids that flow along microchannels. For the development of complex prototypes, many microfluidic test structures are required first. Normally, these devices are fabricated via photolithography. This technique requires a photomask for transferring a pattern to photoresists by exposing with UV light. However, this method can be slow when a new structure is required to change. This is because a series of photomasks are needed, which is time consuming and costly. Here, we present a programmable proximity aperture lithography (PPAL) technique for the development of microfluidic prototype in poly(methyl…